I recently installed a new PSU(antec trupower 650w) and a new video card(geforce 8600 gts) thats when the problem started. I got to play a little bit of HL2 in high but when I tried vegas it hanged. I thought it was just normal so I just restarted the pc, but then it would either do the following: -hang after the windows loading screen, the HDD isnt reading -it would reset it self after the windows loading screen -it would show the blue screen system error thingy after loading windows, then resetting itself. -or it would go through, if im lucky. so i thought formatting would help, but now it does the 3 things(above) when its already loading the setup files(after reformatting). now i dont have an OS just a reformatted HDD im not even sure if it formatted all right.. please i need help, i need my pc for a project. is the problem my video card? is it the mobo? is it the hard drive?