okay im not sure where to post this cuz i dont know where the problem is. but heres the problem. yesterday i was testing my brothers system performance. i kinda thought his video card was setting his system back in benchmarks. its a Nvidia 5600 256MB. so i switched it out with a new Radeon 9600XT 256MB. i turned on the computer and it started to bootup, showed the splashpage then screen went blank *with the 9600*. so i put back in the 5600 and it did the same thing. my brothers computer wont show anything after the splash page. it just says windows xp home edition then after it finishes loading the screen goes blank and suddenly the hard drive starts thinking like crazy and nothing happens. ive run out of options. ive tried everything to fix it. if anybody knows what im talking about please help me out. could it be the video card or the motherboard? agp port go out? something? your help would be much appreciated.