So i scored myself a computer (hp pavilion t620s) and i am ungrading the ram - it had 256 DDR SDRAM 266, i added 1gb DDR SDD RAM 400... when i start up the computer it starts and so on, i can open the hp system menu screen. The computer has fount the both the ram chips, and i havenot changes anything else, but when i exit that to boot it up regually, it will not work.... So the HP screen show blah blah blah, then the computer just shuts down and starts up and the hp screen comes up and so on and so forth... it will not boot windows!

what have i done, how can i fix it (if i didnt screw it up big tme....)

Thanks

Ryan