Blue Screen Error On Cold Boot or Restart

Cold booting sends me to the blue screen of death with the
error message:
An error was detected. Press enter to continue or press
ctrl, alt, delete to reboot. you will lose unsaved info.
All key strokes are dead and the only thing that works is
shutting off and turning on again. Usually end up in safe
mode and need to restart to get to the desktop. Sometimes
it will take several itterations to boot up.

The pc works perfect once booted. If I upgrade to XP will
the problem go away, or does it need to be fixed first?
How do I fix this? Help!

ron