Open a command prompt window.
Start | Run | Type: cmd | OK
Insert your XP CD into the drive and enter the following (Copy and Paste)
command:
EXPAND -R X:\I386\c_437.nl_ C:\WINDOWS\system32\c_437.nls
NOTE :
Change X to = your CD drive letter
Or enter Bios set first boot to CD rom put in XP disk and run recovery console for C drive.
Or
How to recover from a corrupted registry that prevents Windows XP from starting