windows 7 shutting down randomly
I just installed a new motherboard in my HP Pavilion dv5000 laptop. I installed Windows 7 Ultimate. Now when I run windows it will just randomly shut down. Even when I was installing windows it shut down twice in tell I got it installed. I have check to see if it is overheating and it is not. If I run windows in Safe Mode it WELL not shut down as a mater of fact I am writing thes message from Safe Mode. It has been on for 2 hours without shuting down.
When I reboot to regular mode it will shut down within a few min.
What should I look at or is there a program I can run to find what is wrong.
I have already checked for virus.
I also reinstalled windows from scratch 3 times.