I just built my first rig a week or so ago. I'm not the most experienced troubleshooter.
Intel i7 920, not currently overclocked
Asus P6T LGA
XFX Radeon 5770
G.Skill 3x2GB DDR3 1600
Corsair TX 750watt PSU
A single SATA WD Caviar Black 640GB
A single SATA Lite-on CD/DVD burner
Building went just fine- everything posted right away. I set up a Windows 7 Professional 64-bit and Ubuntu 9.10 dual boot. Two partitions for the two OSes, and a third for general storage. My copy of Windows 7 was purchased from my university's webstore, and the .iso burned to DVD using ImgBurn on a slow speed. The installs went smoothly, everything operated well for about a week.
I started to get some error message about win32kernell.dll being messed up. I thought I might have let AVG move something it shouldn't have. Then on a reboot, I got the "Windows was unable to start" jazz and the repairer, which eventually let me back into the OS, which was still not running smoothly, same error. I didn't have much installed on the machine yet, and decided to just do a new clean install from my install disk rather than mess with it.
Windows 7 reinstalled smoothly on its partition, if slow, and it seemed alright again for about a day. I then started receiving errors about installers not being able to run properly, and then on reboot, Windows was unable to start again. The repairer got me into the OS, but Windows Explorer was crashing every three seconds and it was unfortunately rather fubared.
Tried to clean install again and got right up to the end before getting a message that Windows 7 could not set up on my hardware.
The hardware seemed to work fine once, so has something failed recently, and how should I go about testing? If not that, please share. I could try completely reformatting the entire hard drive, not just the Windows partition, but I don't know if this would do any good. If I'm doing something terribly newbish, I apologize for my ways!