Windows could not start, file corrup or missing error message

I have a desktop computer with Windows XP.
There is an error message:
""Windows could not start because the following file is missing or corrupt:
\system32\ntoskrnl.exe.
Please reinstall a copy of the above file."

I tried the system recovery reboot from the computer and using the disc, but I couldn't do it. I don't know what to do next. Please help. Thank you.

Hi, this link will solve your problem

More: http://computerworld.com/issues/ch000646.htm

The link you posted is not working.
But I found the problem. I think the keyboard is dying and causing problem. After I unplug it and restart the computer, it works. thanks anyway.

On that link, you could find that case