Windows XP has the ability to repair itself from 3rd party software overwriting important system files. To fix this we will use a utility called System File Checker or sfc for short Parameters /scannow : Scans all protected system files immediately. /scanonce : Scans all protected system files once. /scanboot : Scans all protected system files every time the computer is restarted. /revert : Returns the scan to its default operation. /purgecache : Purges the Windows File Protection file cache and scans all protected system files immediately. /cachesize=x : Sets the size, in MB, of the Windows File Protection file cache. /? : Displays help at the command

Necessary Things: Windows XP Home/Pro system depends on your Operation System (O/S)

(1). Go to Start then run and then type sfc /scan now. It will prompt you to insert a cd

(2). Insert the cd and let the SFC utility run

(3). what’s going on? The SFC will check your changes to the main system files.