Did you try a newer bigger PSU?
I am Using Windows 7 Ultimate.....
My system is geting restarted again and again on its own whenever I use aero theme.
Otherwise it restarts automatically after 30-40mins.
I had already instaaled a new fresh copy of my OS but the problem still persists.
RAM is working fine and also processor as the same is happing even after replacing RAM and Processor.
4 GB DDR 3 RAM
Quad Core LGA 775 processor.
p5g41t-m lx ASUS Motherboard.
In BIOS power manaement there is a problem in 3.3V its turned red and its 2.86V is comming.
Is there problem with my SMPS or board?
Thanking you all in advance.