Hello, I am new to posting on the forums; however, I have resolved issues here in the past, before. I recently upgraded my computer from an e6400 to an e8400. In doing so, I also upgraded my GFX card from an 8800gtx+ to a XFX GTX 280 xxx edition. Things were fine until the computer decided to randomly start hard locking (sometimes the screen would still display on the monitor, but no response from any peripherals. Other times the screen stays on, but seems to be getting no signal from the video card.) If this annoyance occurs during bootup, the computer would just reboot. I reinstalled Windows 7 Ultimate N, rewired the power supply and reseated the heat sink, and the random reboots during bootup have seemed to stop. YAY ...not During the Windows 7 install on a formatted HD, the computer froze once. 2nd attempt of install went just fine. When I got into Windows, first thing I did was install the 196.75 driver from nVidia. I tried rolling back to the .26 driver version on the previous windows install, so I decided to go ahead and go with the newest version with the new OS install. For the most part, this freeze seems to primarily occur when I play a video game (WoW, to be specific) for about 4-15 minutes. Although sometimes I can get lucky and have it run for 24 hours. So it seems the computer is much more reliable to boot into Windows, but I still cannot play games. I have actually tried troubleshooting many different devices: Swapped out the PSU Swapped out the GPU (used a GTX 260) Swapped out the RAM (ran memtest x86 through 3 passes on all the RAM) Under heavy load, my CPU never gets hotter than 56c, mobo shows 36c I have also tried running many different diag tests. Ran and passed tests on all the following using a Geek Squad MRI disc: mobo, processor, memory, hard drive, graphics, all the cached memory, etc. The GTX 280 did show the PSOD (Pink screen of death) a couple times, but not until after the problem really had established itself for a month or 2. My current setup that I'd like to keep (lol): eVGA 680i SLI mobo 6 gigs of RAM XFX GTX 280 xxx edition graphics WD SATA HDD 500gb Windows 7 Ultimate N (x64) I will be glad to provide feedback on anything you need as far as the computer specs are concerned. Thanks in advance for any troubleshooting support.