Hello, Im having problems with my windows on start up, let me explain everything first, around a month ago I bought a new graphics card without doing reasearch on if my psu could handle it etc, the video card is ati raedon 4670, so after two weeks of having card running it began to freeze on the windows start up (when the green bar is loading), so then I began to look into the problem, turns out my psu was 250W while I required 400W for the card, so I bought a new psu that is 500W, and still same problem, I did restore to original factory condition and it worked! Well only momentarily, around after two days of using it same problem occured, I also noticed that when i left the windows idle for a while it would restart by itself and when it started back up it would freeze on start up, so if i tried to turn on again, same thing, so I left pc alone for a while came back and it would start, no freeze on windows, however this cept happening and now I'm back at where I started, freezes on windows start up, won't start up even if I leave it alone for a while, I've checked all the bios settings etc, reset to default, system repair, everything , and still won't start up, I've talked to some people, currently there is 3 solutions at the moment, 1) swap old motherboard for a new one, 2) replace fans considering that it felt pretty warm with new psu and the fans are around three years old, 3) upgrade my windows meaning switch from my current windows vista home premium to windows 7 home premium, 3 different people had this problem and this is what solved it for them, I need help and feel free to suggest solutions and thank you for helping. My desktop is a dual core E2220 with ddr2 memory and 500gb harddrive, sorry I don't know what motherboard I have but I will look for it. One thing I do know is that it has a built in NVIDIA GeForce 7100