Not loading up and freezing

[maxgraphix]

First, it takes 3 or 4 trys to get the computer to load. Hit the button and within 4-5 seconds, lock-up. Hold the button in, shuts down, try again. Once started it stays started. 9-10 times a day screen freezes, turns completely black, then suddenly comes back. Does this sound like power supply or video card? Also when the computer locks up is before the Bios screen, if I get the Bios screen the I know its gonna start fine. Thanks

 

[maxgraphix]

The video card I have now is the GeForce 5200 - the computer is a 2008 - running XP, and I'm not a gamer but a graphics designer. Not sure if that helps. When I say she locks up on start-up, it doesnt come close to the windows log in screen before it freezes. Compac Presario 2.5 desktop.