I went to a store called 'Best Buy' and had them pick out the 750Ti, and had them install it too, I came back later and they said that my power supply might be good for it, but my mother board seems to not support it or something. Or they just messed up and installed or plugged something in wrong. I trust them but not 100%. The people that set it up gave me a 100% refund and my computer back of course. I don't know what went wrong or why it didn't work. Can someone tell me why it may not have worked or what happened? I looked at the 750Ti box and it said I need a power supply of 400W or greater and I have 500W, so I'm pretty sure its not that, I'm pretty positive that its my Motherboard that isn't compatible, I did do a lot of research on my motherboard, and you people say it should work, but it didn't. So please explain why it didn't?