System files are the hardest working files in your computer: they literally "drive" the computer and house the "drivers" for your mouse, printer, and monitor, among others. Every application you install has its own set of system files, so when an application stops working or won't open, there is a strong possibility that something could be wrong with its system files. These files reside in the C:\windows\system directory and usually have extensions such as .386, .COM, .DLL, .DRV, and .VXD, among others.
The Windows 98 System File Checker scans all the system files searching for any that may have been modified or corrupted by a recently installed program. If it finds a problem file, it prompts you to restore the original file from the manufacturer's install disk. If you ignore the prompt, you'll be asked about it again the next time you run System File Checker.
To run System File Checker:
1. Click the Start button, point to Programs, point to Accessories, and then point to Select System Tools.
2. Click System Information.
3. On the menu bar, click Tools.
4. Click System File Checker.
5. Choose either Scan for altered files or Extract one file from installation disk.
If you choose to scan for altered files, Windows 98 will prompt you if it finds any corrupt or modified files. Follow the instructions on screen. However, if you know the file name, you can extract the file yourself.
Here's how to do it:
1. Select Extract one file from installation disk.
2. Either type the file name or click the Browse button to find the file.
3. When a file name is entered, click Start
4. In the Extract File dialog box, type the path from where the file will be restored, or click Browse to find the folder that contains the file. If Windows does not recognize the file you wish to back up, you may have to manually enter the path in Save file in to where the restored file should go, or click Browse to locate the folder where it should go.
5. Click OK.
Note: You may not see the file you need on your install disks because it may have to be "extracted" from a compressed file.