This teaches you to recovery our window xp when it says *.* file is missing or corrupt on booting.
- You should have a Bootable window's xp CD with its key.
- Start your computer and look for the file that is missing or corrupt. (say NTOSKRNL.EXE)
- Eject the tray of your CD/DVD ROM, put CD into it and thenrestart the computer.
- Now press any key to boot from cd and follow the instructions.
- Press R for recovery console, when the below screen appears.