Check for Corrupt System Files

Did you ever have the suspicion that one of your Windows system files was corrupt? Normally, this problem causes lots of frustration while you try to hunt down the impaired file or do a complete re-install of Windows. Well, hold your Install Disks! There's another way.

Prior to Windows 2000 the operating system might overwrite shared system files (for example .dll and .exe files) when you install software. Overwritten system files cause unpredictable system performance, strange program behavior, and operating system failure.

If you're using Windows 98 you have a way to repair these files with the System File Checker. Here's how:

1. Click Start, Programs, Accessories, System Tools, System Information.
2. Once the System Info utility is running, click the Tools menu, System File Checker.
3. You will be presented with a screen that allows you to "scan all" to hunt for any altered files or to specify the problem file. Since you probably don't know which file is giving you the headaches, scan for altered files.

That's it. If there's something wrong, you'll be given instructions for repair.

One more thing, if the System Information program is not there, you'll need to insert your Win98 install disk, select Add/Remove, and select System Information from the System Tools section.

Windows 2000 & XP users: You will not find System File Checker in your system tools, but if you search for it you will find it as "sfc.exe". No need to run it though, because Windows File Protection prevents the replacement of protected system files such as .sys, .dll, and .exe files. If you do run SFC, you will probably see a DOS window flash on your screen for 1.5 seconds.

Windows File Protection runs in the background to protect all files installed by the Setup program. Any attempts by other programs to replace or move a protected system file are detected, then the file's digital signature gets checked to see if the new file is the correct Microsoft version.

If not, the file gets replaced from the backup stored in the Dllcache folder or from the Windows CD. If Windows File Protection cannot locate the correct file, it prompts you for the location.

By default, Windows File Protection is always enabled and allows Windows digitally signed files to replace existing files.

Posted in: System Maintenance