Tech notes for Windows, and hardware/networking

is my file of notes on computer troubleshooting, tweaking, and the like. Most of the things here apply to Windows 98, and many also work with Windows 95, 2000, NT, ME, XP, etc.  If you need help with anything, feel free to email me.

Disclaimer: This information is presented as a resource to aid in troubleshooting computer problems.  However some of the information is very technical, and you should not attempt to use any of it unless you are already familiar with the general processes involved.  Depending on your computer / configuration / problem, the information here may not help and may even cause more problems, including but not limited to loss of your data.  I disclaim any and all liability for your use of this information, and cannot be held responsible for any damage that may arise from such use.  By using the information presented here, you certify that you have read and understand this disclaimer.

Instructions: either peruse this page, or use your browser's Find function to search for some terms regarding the problem you're having.


Table of Contents

Software: Operating Systems
Software: Specific Programs
Windows 2000 / NT specific issues
Windows XP issues
Web Programming
Server Security
Random Cool Tricks


Linux help

How to make your computer quiet

Battery information

[ Links to more information are at the bottom ]



Problem Solution
My 3dfx Voodoo card will only let me use 640x480 resolution. In the Device Manager, change your monitor type to Plug and Play monitor (it is probably set as "default monitor" which may be the problem).
My printer prints out garbled nonsense. Try changing the parallel port speed in the BIOS.  Some printers, especially older ones, need the LPT mode to be set to SPP instead of the newer, faster EPP or ECP.
General Good Advice: Every so often, boot into safe mode, go to Device Manager, and look for "double driver" syndrome: multiple instances of the same device.  For example, you might have two "Default Monitor"s there.  Remove both (not just the extra one) and restart in normal mode -- Windows will find the correct one and install it.  Also, remove any devices that you no longer have... old hardware that you upgraded and replaced is often still present here, lurking in the guts of Windows.
What is a CDrom, DVD, CDRW, and what's ATAPI, IDE, etc? Check out an optical devices FAQ here or here.
What is the Master Boot Record (MBR)? At the end of the ROM BIOS bootstrap routine, the BIOS reads and executes the first physical sector of the first floppy or hard disk drive on the system. This first sector of the hard disk is called the master boot record (or sometimes the partition table or master boot block). At the beginning of this sector of the hard disk is a small program. At the end of this sector is where the partition information, or partition table, is stored. This program uses the partition information to determine which partition is bootable (usually the first primary DOS partition) and attempts to boot from it.

This program is what is written to the disk by FDISK /MBR and is usually called the master boot record. During normal operation, Fdisk writes this program to the disk only if there is no master boot record.

NOTE: FDISK /MBR only re-writes the MBR on the system drive (DISK-0) using BIOS calls. You cannot specify any other drive for FDISK /MBR to operate on other than DISK-0.

[ from ]

What video card do I have?  (Or, detecting hardware) To find out what kind of video card you have, without opening the case, you can use the MS-DOS debug command.  (I imagine that this can be used to determine lots of other useful things too...)  Go to a DOS prompt and type debug, then press enter.  You'll be prompted with a dash.  Type one of these four things to get video card information:

d C000:0010 <enter>
dc000:35 <enter>
dc000:50 <enter>
d c000:0040 <enter>
d c000:0090 <enter>

...and you should see some video card info on the far right.  To continue, like the "|more" option for the TYPE command, just type:

d <enter>

And, type q <enter> to exit.

 and ]

What do I do about drive controller errors in my Windows event log? Try lowering the drive's speed from ATA100 to ATA66.

[ from a newsgroup post to microsoft.public.win2000.hardware on Sunday, October 28, 2001. ]

How do I set up and use an offboard drive controller? I recently set up a Promise Ultra100TX2 drive controller.  This is a PCI card that has 2 IDE ports on it, which allows you to connect up to 4 IDE devices (hard drives, CDrom drives, etc).  The benefit of this is that 1) it bypasses the BIOS limitations of older motherboards, so that you can use the latest hard drives and CDroms in your older computer, and 2) the transfer rate is (usually) much higher than your onboard IDE controller can provide.  Plus, they're pretty cheap -- Promise is probably the most reputable brand for these cards, and they sell this one for only $30.00.

My problem was that I wanted to put a 40gig hard drive on my Alton/PCchips m571 socket 7 motherboard (running a speedy 233mmx Pentium), to run as a dedicated server.  But the BIOS on this motherboard doesn't support drives bigger than 36gigs, so I had to buy an external drive controller.  Problem solved.  Well, almost, because I couldn't figure out how to boot the thing without using the onboard IDE controller!  But here's what I learned: I needed to go into the BIOS and change the setting "Try other boot devices" to "enabled."  Problem solved, really.

Note that you may also want to disable the onboard IDE controller in your BIOS, to free up the IRQs that they use.  Otherwise you might not have enough IRQs to keep all your devices happy once Windows loads.

The computer locks up when I double-click "My Computer" (or run some programs...) It may be that one of your drives is failing.  Try disconnecting the CDrom and any other drives (Zip, etc.) and then see if the problem persists.
How can I turn on an ATX power supply without connecting it to a motherboard? On the ATX connector, connect pin 14 (should be a green wire) to a ground pin (any of the black wires will do, like pin 13 or 15).  When you disconnect pin 14 from ground, it will shut off.

Check out these diagrams to see the pinouts:

AT power supply connector
ATX power supply connector
How do I mute the modem speaker? In the modem's properties (usually accessible via control panel), there may be an option to adjust the modem volume, or to disable the modem speaker.  If that doesn't work, go to the "extra initialization commands" section in the properties sheet, and add atm0 (that's atmZERO) to there.
My motherboard has on-board sound... how do I know which pins on the motherboard's sound/gameport header are used for the left, right, and ground of the audio output signal? I had this problem; a motherboard I bought had onboard sound but didn't come with a connector.  I had a couple extra ones laying around, but I hooked them up and got no output, so apparently the pin configuration was different on this new (old) motherboard I bought.  This board was an ATC7110M, made by Atrend.  So I hooked up my oscilloscope, played a music file, and tested the 26 pins to see which one had an AC waveform on it.  On this connector, the 26 pins are laid out in 2 rows of 13, and it turned out that the 5th pin down in each row is an audio out signal (one is left and one is right, I'm not sure which though).  These pins had a DC voltage of about 7 millivolts.  Then, going down from the top of the header, the second and fourth pairs of pins seemed like they could be audio ground (based on their ~0 resistance with the chassis-ground and their 0 voltage); I used a pin from the fourth pair and it works fine.

And it turns out that if I take that connector I had -- the one that didn't work -- and plug it into this header upside-down, then these 3 pins I found are connected to the line-in jack.  So I use that for my line-out now.


Software: Operating Systems

Problem Solution
There's a program that starts every time I start Windows, and I want it to go away. See what's starting by checking:
  • the Startup folder on the Start Menu
  • your autoexec.bat and config.sys files in the root of your boot drive
  • your win.ini and system.ini in the Windows folder
  • these registry keys:



    Just delete any items in there that you don't want to start up.  This doesn't delete any files from your computer, or uninstall any programs, it just prevents them from starting when Windows starts.

Also, check out more possible registry hiding places thanks to

Note that you can access most of these items all-at-once by clicking the Start Menu, then Run, then type "msconfig".  If you've got Windows 2000, you can copy the file msconfig.exe from a Windows 98 machine -- it will run fine on Win2k, just ignore the errors it gives.

Also, on Windows NT, some programs (like antivirus software) run as services, so you may need to change them from Automatic to Manual services if you don't want them to start everytime you boot.

My computer freezes shortly after I start to install Windows 9x. Possible solution: disable the virus protection in the BIOS.
There's an icon on my desktop that I want to get rid of. Click Start, Run, and type "regedit".  Then go to


The keys in that folder are for the extra desktop icons.  [Alternately, you can get TweakUI, which allows you to remove some desktop icons.]
How can I save a file with a different extension than the file type's default extension? NOTE: This question only applies if you have Windows set to hide your file extensions.

When you're in a program like Notepad, for example, if you type up a file and save it as myFile.htm, it will actually be saved as myFile.htm.txt, because Notepad's file type is txt (for text document).  But since your file extensions are turned off, you won't see the .txt on the end of it.  To continue the Notepad example, the problem with this is that .htm files should open in your internet browser, but Windows is hiding the real extension from you, which is .txt.  The result is that your file that you want to open in your browser is instead opened up in Notepad.

To get around this, you can turn your file extensions on, or, you can save the file as "myFile.htm" (make sure you add the quotes or .txt will be added to the end).

How do I make my ASPI work correctly? ASPI is a method Windows may use to access data on your CDrom discs.  You may run into trouble with this when trying to use various mp3 tools.

I put together a small zip file with everything you need... click here to get it.

How can I see what processes are running on a Windows 98 computer? Start Microsoft System Information (msinfo32) and look under the "Software Environment" section.
How can I easily get to a command prompt from any folder, so I don't have to cd to the folder I want? Open your registry and find the key:


Create a new sub key called 'CommandPrompt' and change the value of '(default)' within the key to equal the text that you would like on the right-click menu, for example 'Command Prompt Here'.

Within CommandPrompt, create another new sub-key called 'command' and change the value of '(default)' within this key depending on your operating system:

Windows 9x /k cd "%1"


Windows NT
cmd.exe /k cd "%1"

Now right-click on a folder and the new option of 'Command Prompt Here' should be available.

When I dial up to the internet, it connects and verifies my username and password, and then it disconnects. You might not have the necessary protocols (usually TCP/IP) bound to your dial-up adapter.  Go to Control Panel, Network, and then find your Dial-Up Adapter and click Properties for it.  Under Bindings, make sure you have it bound to TCP/IP.  (You might not have TCP/IP installed at all, in which case, you need to go to Control Panel, Network, click Add, Protocol, and add TCP/IP.)
Where can I get a boot disk?

First of all, Then, here are the files from boot disks that I frequently use.  Note that the files alone don't make the boot disk -- you also need some method of writing to the boot sector of the disk, to tell it which boot files the computer should be looking for on the disk.  In Windows 95 and 98, when you right-click the floppy in My Computer and choose "Format", it gives you the option of copying the system files.  When you select that, it also prepares the boot sector of the floppy disk.  Then, when you boot from that floppy, the computer looks at the boot sector and sees that it points to the system file, so the computer checks the floppy for that file and loads it.  Without the boot sector's direction, the computer doesn't know from any other file... for example, Windows NT boots from a file called ntldr ("NT loader"), so the boot sector on an NT boot disk points to that file, not

All are self-extracting archives, about 500 - 700 kilobytes each.

Windows 95a

Windows 95b

Windows 98 OEM

Windows 98 (my homemade disk) with CDrom driver & all the good commands

Windows 2000 boot disk / "emergency repair disk"

Sometimes when I save a text document, all the line breaks get removed, so the text is all "wrapped" onto one lines, or scrunched together at the top on a few lines. As best I can figure, this issue involves a file that was saved with a slightly different text encoding, or on a different OS where the line feeds / carriage returns are handled differently.  For example, if you have a website hosted on a UNIX computer that you use FTP to access, but you run Windows on your computer, this might happen.

The only fix that I've found is to open the file as a text document in MS Word, then choose File, Save As, Text Document or Plain Text.  This should give you a dialog box with options.  If you choose Windows encoding, and check the "insert line breaks" box, it should save properly.  Then you can edit the file in Notepad or wherever, and it should be just fine.

How can I add an item to the right-click menu for files on my computer? Simple.  Open regedit and go to the appropriate HKEY_CLASSES_ROOT subkey for the filetype you want (for example, HKEY_CLASSES_ROOT\jpegfile for JPEG images).  Open the shell key, and within that create a new key for your command.  Set (Default) to the text you'd like to appear on the right-click menu (with an ampersand before the character that you want to be Alt-key accessible).  Then, within that key, create a sub-key called Command, and change its (Default) value to program.exe -options %1 (%1 [that's percent-one] is the file that you right-clicked on).  Press F5 to refresh the registry, then close regedit, and you're done.


Software: specific programs

Problem Solution
AOL freezes right after I click the "Sign On" button. Possible solution: McAfee's antivirus program has a component called webscanx.exe, that is always running after you install VirusScan.  Certain versions of webscanx.exe cause this problem with AOL.  Press Ctrl-Alt-Del (and if you're using Windows NT, then press "Task Manager" followed by "Processes") see if webscanx is running.  If it is, then stop it by highlighting it and pressing "End Task".  Now see if AOL works.

NOTE: an AOL problem can be caused by a zillion different things; this is just a suggestion at one possible cause and solution.

How can I clear my Internet Explorer temporary internet files (cache) automatically? For Windows 95/98, you can add these lines to the file c:\autoexec.bat, and then every time you start your computer, your internet history, cache, and cookies will be deleted automatically.  Note that on some older hard drives, this may take a minute or two.

attrib c:\windows\tempor~1\*.* -s -h -r
echo y|del c:\windows\tempor~1\*.*
deltree /y c:\windows\tempor~1\*.*
attrib c:\windows\cookies\*.* -s -h -r
echo y|del c:\windows\cookies\*.*
attrib c:\windows\history\*.* -s -h -r
echo y|del c:\windows\history\*.*
deltree /y c:\windows\history\*.*
attrib c:\windows\locals~1\tempor~1\*.* -s -h -r
echo y|del c:\windows\locals~1\tempor~1\*.*
deltree /y c:\windows\locals~1\tempor~1\*.*

For Windows 2000, there's a little more to be done.  First, you need to scroll down a bit and learn how to create the service AutoExNT on your system.  Once that is done, you can add these lines to your autoexnt.bat file, substituting your login name for loginName.  (You can remove the pause and echo commands if you like; they're just there to provide feedback for you as the process goes on.)  But note that the file index.dat within each folder will not delete, because it's in use.  For NT it's best to boot from another NT hard drive and manually delete the cache on the non-active drive.

In WinAmp's playlist editor, when I click the plus sign to add files to the playlist, it doesn't remember the last directory I added files from. WinAmp seems to be quirky about this, but I think I know what's happening.  When you click the plus sign and add files, you can select a bunch of files (by dragging a box over them, or pressing Ctrl+A, or holding Shift or Ctrl while clicking), and then press Open.  But then it doesn't remember that directory next time you try to add files.  To make it remember the directory, you have to double-click on a single file (which bypasses the need to press the Open button).

Note: In newer versions, this problem may not occur.

Also in WinAmp's playlist editor, it displays the ID3 information as the song title, but I want it to use the filename. In WinAmp...

Select "Nullsoft MPEG Audio Decoder..."
Title Tab
UNcheck "Use ID3v1/2 Tags"

The right-click menu (aka, context menu) in Internet Explorer is really slow to open! It's a bug in IE because of some null registry entries.  You can read about it and download a fix called MIE55SpeedUp.exe here.
How do I set up Audiocatalyst to make mp3s from CDs?

I used to use Audiocatalyst, until I found out about the LAME mp3 encoder, which is the best one available.  And, it's free.   At the same time, I also found out that Audiocatalyst was cutting the high end off many of my mp3s, and after listening to LAME-encoded mp3s, the difference is clear.

Don't use Audiocatalyst.  Use Exact Audio Copy to rip your CDs to wav files, then use LAME along with my LAME frontend to make mp3s from your waves (and automatically set the ID3 tags), which are all free. 

If you insist on making bad-sounding mp3s with an encoder that costs money, here are some instructions on how to set it up.

How do I disable autorun for my CDrom drive? Download this text document and double-click on it... it will add the appropriate settings to your registry.

[ source ]

How do I make all unknown file types open in Notepad? Download this text document and double-click on it... it will add the appropriate settings to your registry.

[ source ]

How can I enable Windows Media Player (WMP) to play DVDs? To do this, you MUST have hardware-based support for playing DVDs (in the form of a dvd decoder card, or a video card that has dvd decoding built in).  Then you can make the following registry change to enable WMP to play DVDs:
  1. Start regedit.exe.
  3. From the Edit menu select New, String value.
  4. Enter a name of EnableDVDUI for the new string value, then press Enter.
  5. Double-click the new value and set it to Yes. Click OK.
  6. Close regedit.
  7. To start playing DVDs, select File, Open, DVD, then click Play.

[ source: ]

How do I use the GIMP? GIMP is a great image editing tool comparable to Photoshop, except it's free.  You can use it on Windows and Unix/Linux.  Click here for a little guide on how to use it.
All my unassociated files are opening in WinAmp!! In WinAmp preferences, under Setup \ File Types, uncheck "Register types on Winamp start" if it's checked.  Then close WinAmp.  Run regedit and go to HKEY_CLASSES_ROOT\. (note the period!!), and delete the text "Winamp.File" from the (Default) key.  Now restart.
My video program (Windows Media Player, etc) won't play some AVI files... the sound plays, but no video. You probably need to download a DivX codec.  Here are some links that will help:

If you try to play an AVI file and you get an error that says "this is not an avi file" or "not an avi file", it might be an Ogg Vorbis encoded AVI file.  (If you view the first few lines of the file in a hex editor, it may say something about DirectShow something-or-other, like "OggS55LDirect Show Samples embedded in Oggvids".)  Anyway Tobias Waldvogel wrote some files that you'll need; download that package (remove the .php extension if there is one) and run it, and it will install the files you need.  Then your "not an AVI file" should play just fine in Windows Media Player or whatever.

Problems with Apache / Perl...

If the problem involves HTML or Perl code, or configuration files, or anything where files/paths need to be referenced, the solution might be to put a forward-slash at the beginning of the filename or path name.  This has been the answer to a few different problems I've had with Apache.

Remember that you can't put images in your cgi-bin directory and expect them to load correctly when called from a browser.  Apache treats everything in that directory as an executable script.

If you want to run Perl scripts with Apache on Windows, your shebang line will be different than the standard #!/usr/bin/perl found on *nix Apache.  You'll need to use the full path to perl.exe including the drive letter, like #!c:\perl\bin\perl.exe .

You DO NOT need to escape forward-slashes in Perl code with back-slashes.  For example, if you wanted to load the Google logo as the background of your webpage, you would NOT use this:

<body background=\"http:\/\/\/images\/logo.gif\">

Instead, just use this:

<body background=\"\">

Some characters, like the double-quote character, DO need to be escaped with the back-slash.  But forward-slashes do not.

Internet Explorer won't download more than 2 files at a time. This behavior is by design, based on rfc2068.  To circumvent it, click Start, Run, and type regedt32, then go to this key:

\Windows\CurrentVersion\Internet Settings

On the Edit menu, click Add Value, and then add the following values:

MaxConnectionsPer1_0Server, which gets a Dword value of 0000000a (hex).

MaxConnectionsPerServer, which also gets a Dword value of 0000000a (hex).

That's it.

[ source ]

Internet Explorer freezes / Internet Explorer pauses / Internet Explorer hangs when a new window pops up. This happens when the javascript method is called and the second argument (the window handle) is NOT null.  For example:"","google") the handle is "google", thus not null, so IE will pause for anywhere from 5 to 30 seconds or so, until the window pops up. However, this code:"","")

...will pop up a window instantly, because the handle is null.

Here's an example:
This popup uses a null handle for ) [should be quick].
But this popup names the handle for ) [should hang Internet Explorer for a while].

The root of the problem appears to be the number of Internet Explorer windows that you have open.  I (used to) always have 5 or 10 open at a time, and the "hang" would last for over 10 seconds.  But if I have only one window open, then the popups happen almost instantly.  I think that what's happening is that IE is checking the handles of all the open IE windows, because if there's an open window with the handle that is using, then the link will open in that window instead of a new window.

In any event, that should not take a long time.  My conclusion is that this is an IE bug (or just plain inefficient coding), and my current workaround is to reduce the number of open IE windows that I have use mozilla instead of IE, because it's so much better in every respect anyway, and it doesn't have this bug.


Issues Specific to Windows 2000 and/or NT

Problem Solution
How do I add stuff to the boot menu in Windows 2000? The file boot.ini, in the root of your boot drive, stores these settings.  Hack it and use the existing options to learn the syntax for adding your own options.
I get a "drive is not accessible" error when trying to read a drive, and the drive's name is showing up incorrectly, but Admin Tools > Computer Management > Disk Management shows the drive/partition correctly. Possible solution: right-click on the drive and choose Properties, then on the Security tab, and then add yourself (or just add "everyone", though from a security perspective, it's better to not add "everyone" if you don't have to).
How can I add a Encrypt/Decrypt option to the context menu?
  1. Start the registry editor (Regedit.exe)
  3. From the Edit menu select New - DWORD value
  4. Enter a name of EncryptionContextMenu and press Enter
  5. Double click the new value and set to 1. Click OK
  6. Close the registry editor
  7. Reboot the computer for the change to take effect (or you can start Task Manager and stop explorer.exe and start a new occurance)

If you now right click on a file/folder Encrypt will be listed for non-encrypted files, Decrypt for encrypted files.

[ source: ]

How can I configure NT to display a thumbnail of bitmaps as the icon instead of the Paint icon? Perform the following, for best effect make explorer use large icons
  1. Start the registry editor (regedit.exe)
  2. Move to HKEY_CLASSES_ROOT\Paint.Picture\DefaultIcon
  3. Double click on Default in the left hand pane, and change to %1, click OK
  4. Close the registry editor. The change will take immediate effect.

[ source: ]

How do I change the Internet Explorer icon? For Internet Explorer version prior to 4.0 follow the procedure below:
  1. Start the registry editor (regedit.exe)
  3. Double click Default on the right hand side and change to the icon you require (use browse)
  4. Select OK
  5. Close the registry editor

There is a program called MicroAngelo available from which automates this procedure.  There are some icons there too.

For Internet Explorer 4.0 and newer, the method is as follows:

  1. Start the registry editor (regedit.exe)
  3. From the Edit menu, select New - Key and enter the name of DefaultIcon and press Enter
  4. Double click Default on the right hand side and change to the icon you require (use browse)
  5. Select OK
  6. Close the registry editor

[ source: ]

How can I configure the system so that certain commands run at boot up time? There is a utility called AUTOEXNT which is supplied in a zip file. You use perform the following:

  1. From the AUTOEXNT.ZIP file extract the files autoexnt.exe, autoexnt.bat and servmess.dll to %systemroot%/system32
  2. Also extract the file INSTSRV.EXE to any directory (a temp directory will do)
  3. At the command prompt enter
    instsrv install
    This will create a new service called AutoExNT
  4. Edit the file %systemroot%/system32/autoexnt.bat and put in any commands you want to be run when the machine boots (such as a CHKDSK, etc.)

When the system boots in future the AutoExNT service will check for the existence of the file autoexnt.bat and execute any commands in it.

A version of this is also shipped with the resource kit, however it is better to use the downloadable version. To install the Resource kit version you have to type
instexnt install

[ source: ]

How can I add my own information to General tab of the System Properties in Windows 2000? When you receive a PC from a manufacturer you may see extra lines of description text and a company logo in the General tab of a System Control Panel applet, and this can be changed or added as follows:
  1. Create a bitmap you want with dimensions 172 by 172. Save the picture in the %systemroot%/system32 folder (e.g. d:\winnt\system32) with a name of OEMLOGO.BMP. If the picture is greater than this size then it will be clipped from the top left corner. If it is smaller then a black border will be added.
  2. Create the file %systemroot%/system32/OEMINFO.INI (e.g. d:\winnt\system32\oeminfo.ini) with the following format:
    Manufacturer=SavillTech Ltd
    Model=SuperDuper 1
    SubModel=Optional line 
    SerialNo=Optional line
    OEM1=Optional private info 
    OEM2=More private info 
    Product=Your Product Name
    [Support Information]
    Line1=" "
    Line2="For support ...."
    Line3=" "

You do not need to reboot the machine, the system control panel applet will pick up the files when started.

[ source: ]

What are the Windows 2000/NT system files? the registry - five main keys of the registry, plus system.ini, and win.ini.
autoexec.nt - sets up the configuration of DOS for backwards compatibility only.
config.nt - sets up the configuration of DOS for backwards compatibility only.
cmd.exe - Win2000's DOS. - DOS.
ntldr - used to boot up Win2000. - used to boot up Win2000.
boot.ini - used to display the menu when booting up Win2000.

- used to provide non-English languages during boot up of Win2000.
ntbootdd.sys - used to boot up Win2000 on a SCSI disk.
bootsect.dos - used to boot up other operating systems other than Win2000, like, DOS or Windows 95.

[ source: the help file for WinRescue for Windows 2000 ]

What files make up the Windows NT registry? The files that make up the registry are stored in %systemroot%/system32/config directory and consist of:
  • software - HKEY_LOCAL_MACHINE\Software
  • default - HKEY_USERS\.DEFAULT
  • Ntuser.dat - HKEY_CURRENT_USER (this file is stored in %SystemRoot%\Profiles\%username%)

There are also other files with different extensions for some of them

  • .alt - Contains a backup copy of the HKEY_LOCAL_MACHINE\System hive. Only System has a .alt file
  • .log - A log of changes to the keys and values for the hive
  • .sav - A copy of the hive as it looks at the end of the text mode stage in setup

[ source: ]

More info on these files [from the MCSE Training Guide for Windows NT Server 4, ©1997 New Riders Publishing, ISBN 1-56205-768-5, page 460]:

  • The *.LOG files "are so transitory that they would be useless by the time the backup completes."
  • SAM and SECURITY are off-limits for editing
  • SYSTEM and SOFTWARE are the most important
  • Use the rdisk utility to back them up
How do I back up the Windows NT registry? Possible solution: If you have the Windows NT Server 4.0 Resource Kit, you can use a set of command line tools called Regback.exe and Regrest.exe. With these programs, you can easily back up and restore all or part of the Registry to tape, floppy disk, or just another folder on your hard drive.

[ source ]

A better solution, though, is to create another Windows NT installation on a second partition or second hard drive.  Then boot that installation.  From there, you should be able to see all the registry files you need on the drive where the first installation exists, and you can manually copy them to a backup folder now, since they're not in use.  Then if you ever need to restore a backup, just boot the second installation and copy a backup registry to the first drive. 

When I log into Windows NT, it gives me a "Limited Virtual Memory" error, saying that "Your system does not have a paging file, or the paging file is too small." This could happen if you've changed the security permissions for the folder where the pagefile is stored (usually the root of the boot drive).  On the drive's Properties sheet, click the security (or permissions) tab, and add "SYSTEM" to the list, with full control.
How do I change the logon wallpaper? Go to this registry key:

HKEY_USERS\.DEFAULT\Control Panel\Desktop

...and change the value of the "Wallpaper" item to the path and filename that you want.

Hibernation / APM / ACPI issues? Many motherboards that support APM also support ACPI.  If you have yours set to APM when you install Windows 2000, the OS will set itself up as a non-ACPI system and will instead use APM.  The problem with this is that APM doesn't fully support the Hibernation feature of Windows 2000.  The only way to put your computer into ACPI mode is to enable ACPI in the BIOS, and then reinstall Windows 2000 (note: you can also put in the Windows 2000 CD and do an upgrade which will save you a little time).


Windows XP

Problem Solution
When I search for files or folders on my computer, I get a blank error message, and it doesn't search. Download and install TweakUI if you don't have it already.  Then run it by clicking Start, Settings, Control Panel, TweakUI.  On the Desktop tab, make sure the box that says "Search Results" is checked.



Problem Solution
What is the wiring order for CAT5 network cable, and what about crossover cables? Category 5 (CAT5) network cable is used to connect a computer to a network hub or outlet.  The wiring order is like this:


A crossover cable is a CAT5 cable used to connect 2 (and only 2) computers directly to eachother, without a network hub.  The wiring for crossover cables must be changed a little since there is no hub between the computers.  The change is that you switch the orange and green wires (on one end of the cable only):


Click here for my simple rules... all you need to remember for making cat5 cables.

What is the maximum length I can make my network cables? The total length of wire segments between a PC and a hub or between two PCs cannot exceed 100 Meters (328 feet or about the length of a football field) for 100BASE-TX and 300 Meters for 10BASE-T.

[ source ]

How do I set up a network? There is a guide here, which I've copied locally here.
What is a router? A router is a hardware device that allows multiple computers to share a single connection to an outside network (usually the internet).  It performs Network Address Translation (NAT) in its hardware, as opposed to proxy server programs or Windows' Internet Connection Sharing, which uses software-based NAT.  If you have a DSL or cable internet connection, you probably use client software like WinPoET to connect to the internet.  But with a router, you don't need any client software -- the connection is handled exclusively by the router.

[ Quoth Mark Chasen, a network engineer at Conestoga ]

Can I control Dial-Up connections from the command line? Sure... use rasdial.exe and rasphone.exe in the Windows system or system32 folder.
What is my IP address? I've answered that here.
I have the D-Link di-704 router, and when I browse the internet, some websites cannot be found, while others can. If you have an HTTP server on your local network, and it's configured to accept requests on port 80 under the di-704's "virtual server" configuration page, disable it by unchecking the box for it.  Reboot the router and see if the problem goes away.  If it does, try updating the firmware for the router.


Web Programming

Problem Solution
Home come my content is not vertically centered in Netscape?
There are probably a few ways to make this work, but one way to make it NOT work is to surround the code with <div> tags.  Another way to make it NOT work is to surround a table with <center> tags.  So while this WILL work:
<title>Vertically Centered Content

  <table width="100%" height="100%">
  <tr><td align="center">
  This content is centered vertically.


This WON'T work (in some versions of Netscape, anyway):

<html><head><title>Vertically Centered Content

<div align="center">
  <table border="0" cellspacing="0" cellpadding="0"
   width="100%" height="100%">
  <tr><td align="center">
  This content is not centered vertically in Netscape.

How can I make an IFRAME's background transparent?
In the webpage containing the IFRAME:


<html><body bgcolor="red">

Here's an iframe with a transparent background:

<IFRAME src="iframe-itself.htm" width=100 height=300
 scrolling=auto frameborder=1 allowtransparency>


Then in the page that will live in the IFRAME:


<html><body STYLE="background-color: transparent">

Iframe content goes here...

Why does my perl script give an error when I try to write an HTML page as the output? I have come across a strange thing... it could be just something in my configuration, but just in case it's not, I'm documenting it here.

In this Perl script, you can't have the print(" on the same line as the <html> or it will give an error.  I don't know why.

use Net::Ping;
$host =
$p = Net::Ping->new("icmp");
if ($p->ping($host))
# This won't work:
print("<html>The server at $host is up.</html>");
# ...but this will:
<html>The server at $host is up.</html>");

Why does my Perl script / Apache server try to download my script files instead of executing them, or instead of displaying their output within the browser? This is probably because you don't have a Content-type header in the script's output, or you have it there incorrectly.

You should do this:


print "Content-type: text/html\n\n";
stuff goes here..................</html>

But not this, it won't work, even though it looks like it should do the same thing:


Content-type: text/html\n\n
stuff goes here..................</html>

How do I use .htaccess files in Apache? In your main apache configuration file (usually apache\conf\httpd.conf), do this:

<Directory "D:/usr/www/server/somefolder">
AllowOverride All

...where somefolder is the one you want to put an .htaccess file into.  Note that you don't have to use "All", you can allow only certain features to be overridden if you want.  Also, if you're using MS Windows, it won't let you create files whose names start with a dot, you'll need to call your files something else, like my.htaccess.  Then put this into httpd.conf:

AccessFileName my.htaccess

Now just go to somefolder and create a file named my.htaccess.  You can put lots of stuff into it... see the Apache documentation.  Here's an example that prevents the "Parent Directory" link from being displayed on directory listings:

IndexIgnore ..

So you'd just put that into the my.htaccess file and you're all set.

Other examples:

Options +Indexes  (force directory listings)

IndexOptions FancyIndexing NameWidth=* SuppressLastModified
SuppressDescription SuppressSize
(for directory listings, sets the width of the name column to the width of the longest filename, and suppresses all other columns)


Server Security

Problem Solution
How can I make my Windows computer / server secure?

Turn off NetBIOS over TCP/IP and disable the "Universal Plug and Play" or "UPnP" service.  (UPnP is actually "Network Plug and Play" if we want to be accurate about it.  You can get a utility from that will enable/disable this for you.) Those are the two biggest security risks in Windows.


Email & Web Browsing

Problem Solution
How can I find out what OS and server software are running on a server? You can use telnet for this.  Go to the command prompt and type:

telnet 80

The cursor may jump around the screen; don't worry about that.  You type 80 because that's the port that the HTTP protocol uses.  Otherwise telnet will connect using its default port of 23, and then this won't work.

Now type this, with GET and HTTP in uppercase:

GET / HTTP/1.0

And after you type that, press Enter twice.  This should return either the default page or an error page, but either way it will tell you the server software right at the beginning of the page.

How can I delete an email message from the server without downloading it? You can use telnet to do this.  On Windows 9x or NT, type telnet <server name> <port number> at the command prompt, or after clicking Start, then Run.  Port 110 is where your POP email service typically runs.  The server name is your POP server, where your new email is downloaded from.  Once you type that in and press enter, it will connect, and then just sit there.  Now you're ready to begin acting like an email program.  What you're going to do is talk to the server, via this nifty telnet jammie, and tell it what to do with your mail.

First, type user <username> and press enter.  You should get a confirmation of some sort.  Next type pass <your password> and press enter.  You should get another confirmation here.  Now you're in, and you can check if you have any messages on the server by typing list.  All it will show you is a number for each message and its size.  To view the message, type retr <message number>.  This will display it all on your screen.  To delete a message, type dele <message number>.

Click here for more info on telnet.
I was running Eudora v5.x on Windows XP.  I re-installed Windows and then re-installed Eudora, and tried to copy my old Eudora data folder and use that (the folder containing my mailboxes, filters, address book, etc), but Eudora crashes when I run it. I fixed this problem by going into the Eudora data folder, then into the EudPriv\Ads subfolder, and deleting all the files there (but didn't delete the AdCache folder or its contents).


Random Cool Tricks

Problem Solution
How can I make animated GIFs? I've answered that here.




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