I put together a new system last night and proceeded to install Win 7 64-bit and all was well. It's a legit retail copy of the Win 7 upgrade disk bought from Amazon. After a handful of restarts (Windows updates, driver updates, etc) the computer decided to freeze at the Windows welcome screen (black screen w/Windows logo). I tried booting in safe mode and had no issues. I tried reverting to a previous save state prior to the freeze issues, but that didn't change anything. Safe mode continued to work. I decided to attempt re-installing. Now I can't even get a working install. Windows 7 installs and then restarts. I get the welcome screen and then it goes to a screen where it's starting services, but then it just freezes. I've tried installing multiple times with the same results. Based on some digging in other threads I've tried: 1. Deleting all partitions during the new install and formating a single partition for install. 2. Unplugging all USB devices (only have a mouse and keyboard using USB anyway) during install. 3. Disabling the floppy drive option in Bios (don't have a floppy anyway). 4. Changing SATA in bios to "ACHI". 5. Loading bios "optimized configuration" and "failsafe configuration". 6. Clearing CMOS. Hardware is as follows:Gigabyte GA-P55A-UD3 MoboCorsair CMPSU-550VX 550-Watt PSUIntel i5 750 Processor 2.66ghz 4gb Corsair CMX4GX3M2A1600C9 RAMGigabyte GeForce GTX460-1 GB Video Card WD Caviar 1TB SATA Hard Drive I read in other topics that people have been having issues with PSU's causing freezing. I also noticed some of these issues were with Corsair PSU's. I'm not sure if it might be related in my case. I also assume my PSU wattage is okay given what I'm running, but maybe it's underpowered. I've also noticed that for some reason when the computer posts it shows my CPU running at 2.8ghz instead of 2.66 even regardless of whether I run optimized or failsafe bios settings. Finally, I haven't had a chance to try taking one of my RAM sticks out to see if that's an issue.