Dell latitude error

[cpa]

I have a dell latitude running win xp and got this error message when I try to boot up. Windows could not start because the following file is missing or corrupt: <windows root>\system32\ntoskrnl.exe. Please reinstall a copy of the above file.

Two questions: what could have caused this and how can it be repaired? Thanks

 

[IPBA]

Use your Windows CD and run a repair on the OS. I would also run the PSA Diagnostics to ensure your drive is OK. Either Press F12 at the Dell splash screen or hold the Fn key while powering the system on.