|Your computer itself is booting fine, otherwise you would not be seeing that message. Your problem is Windows is not loading properly.|
I'm assuming that you DO NOT have both XP ans Vista on the computer.
Found on the web...
"This issue occurs if the information in the Boot Manager file is invalid or corrupt.
As of now, I would suggest you to try the steps mentioned below.
Method 1: Perform a startup repair
Method 2: Perform a system restore from Windows recovery options
Windows fails to start with error Missing or Corrupt ntoskrnl.exe when keys are pressed during startup