Clear Bios as suggested & make sure the CPU settings (FSB, voltage etc) are correct. The error message you are getting does not always mean there's anything wrong with the CPU or it's settings.
If you still get a problem after this, look for the setting that determines which errors cause the system to halt - usually termed something like 'halt on ...all errors' etc. If you have such a setting, try changing it to halt on 'no errors' or 'disk & key only'.
Regardless of whether you change anything in the Bios or not, save the settings anyway & do a warm reboot immediately after the system restarts (ie CTRL-ALT-DEL). I usually find this stops the message coming up again.