NTOSKRNL Missing or Corrupt,just follow these steps

If you get an error that NTOSKRNL not found:
1.Insert and boot from your WindowsXP CD.
2.At the first R=Repair option, press the R key
3.Press the number that corresponds to the correct location for the installation of Windows you want to repair.
Typically this will be #1



4.Change to the drive that has the CD ROM.
5.CD i386
6.expand ntkrnlmp.ex_ C:\Windows\System32\ntoskrnl.exe
7.If WindowsXP is installed in a different location, just make the necessary change to C:\Windows
8.Take out the CD ROM and type exit