Just got 2 480GTX's and every time I select "enable sli", the screen would turn black and the computer requires hard reset to get back into windows. After reboot, sli is still not enabled. All connections (power connector, sli bridge, etc) are intact. Using Corsair 1000W PSU to power this + i7 920 (oc'ed to 3.78) + 2 HDDs + 2 SSDs + a few fans. Tried latest official and beta driver and get the same problem. I used 2 460GTX in SLI and did not have this problem at all. Yes, I uninstall original driver and ran driver sweeper prior to install both cards and new driver. I googled around and some people had a similar problem but in their case the SLI option did not show up. My SLI option does show up but enabling it causes the black screen and freeze. Some suggest rolling back Realtek NIC driver (did not work for me). Each card works fine individually. Need help, please!