Computer will not boot after installing SP2

Get a screen which displays:

Out of frequency
HF 83
VF 159
Operating Frequency
HF 30-70
VF 50-160
Power Management (Starts counting down from 20)

At the count down of 15, the system shuts down for about 30 seconds and then
does a reboot which takes it to the screen with the options of " Start
Windows Normally, Safe Mode, Safe Mode with Command Prompt, etc"

If I select "Start Windows Normally" I get the "Out of Frequency" screen and
repeat the above.

At this point I started in Safe Mode, did a system restore to remove SP2,
and disabled Window's automatic updates to get back up and running.

Computer Specs: Abit VT7 motherboard, P4 2.4 GHz, ATI Radion Video card

Tried searching the knowledge base for "Out of Frequency" but got nothing
that seems to apply to this problem.

Anybody have any ideas?

Thanks for any and all help.

Claude