Quote: Originally Posted by
muplayer 
All my settings in BIOS are in Auto or default
Quote: Originally Posted by
muplayer CPU Type QuadCore Intel Core 2 Quad Q9550, 3400 MHz (8.5 x 400)
An Intel Core 2 Quad Q9550 is 2.83GHz. If you're running yours at 3.4GHz, then everything isn't at default. Again, your overclock isn't stable, you said as much when you said you could not pass 20 minutes of a system stability test.
Go into the bios and load the optimized defaults, then see if you still have problems. If you don't, then the "problem" is not your hardware or Vista.