I have a Nvidia GeForce 9500 GT graphics card that I am wanting to trade out for a Nvidia 8800 GTS graphics card. So I do what is obvious, install the driver into windows power down the machine unplug it and switch the cards out, easy, but when I power the computer back on I notice the numlock key doesn't light up and the monitor will show nothing or even wake up from sleep mode. I am running an ASUS M4A78 PLUS motherboard. I notice if I pull the 8800 out it is warm, so I'm guessing that it is processing information, and if I use my second PCI-E slot for it with my 9500 in my main one windows will show that it sees it but wont use it.