Mce 2005 reboots 1 min after starting up

I need some help here!

Mce 2005 pc, starts up,serious error message appears,then 10 seconds later fatal error message flashes up! then 40 seconds later system reboots.

I have tried disabling all start up programs via msconfig which gives me approx 10 seconds more before it reboots. I dont want to have to reinstall the OS again because i only finished rebuilding it 5 days ago after Sp3 screwed up all the codecs and drivers! And the approx 1 min between reboots doesnt leave much time to investigate the cause.

 

You may have to do a repair from your installation disk.

 

I have been looking at Pc beginner as it claims to be able to fix these sort of issues! Any thoughts?

 

can you get into safe mode and does it still reboot

 

I have tried booting in safe mode but F8 doesnt seem to take it to safe mode.

 

tap the "F8 key" continuously to get into safe mode

I have never used it. A system restore would have been my first choice but you don’t have enough time to access it so my next suggestion still is to do a repair from the installation disk.
You can wait until the rest of the world wakes up for further suggestions.