System files in Windows XP may get corrupted because of many reasons like a virus attack, improper Windows shutdown etc. Windows XP has a System File Checker tool (known as SFC in short) which can check all the protected system files against the original versions stored on the Windows XP CD and replace them if it finds them altered or corrupted. The following instructions show how to use the System File Checker :
- Make sure you insert Windows XP CD in your CD/DVD Rom drive before you proceed.
- Open Start Menu → Run, type SFC /SCANNOW and press Enter
- Wait while SFC tools checks all the system files.
Note : You cannot use any other Windows XP CD other than the one that carries same version and service pack as installed on your computer. For example, if you have installed using Windows XP SP2 CD, then you cannot use Windows XP SP3 CD for the System File Check process.