bios issue

My nvidia based gaming built by me system has an issue with the computer
bios. The issue is that when the computer restarts often it goes into bios
safe mode to " reset cpu frequency" press delete to enter bios or f1 to
continue. I have uguru (abit) based motherboard diag software.

If I hit delete enter bios enter cpu area then hit F10 to save its good. If
I hit F1 then it restarts but will crash when I start uguru. Is this a
short on the motherboard. Because changing the cpu didnt help and when I
tried to overclock the cpu I got bios coruption on the screen letters all
over etc like if I pluged in a bad fan or something. Tia Peter