This is a strange problem I have had since both upgrading my hardware and Windows 7 at the same time. It occurred with the final Release Candidate, and is currently occurring with the final version of Windows 7.
What happens, is sometimes (maybe 2 out of 5 times) when I boot Windows 7 does not complete booting; and just hangs at the startup screen. I then reset my machine, and choose to "Start Windows Normally", rather than "Repair" when given the option. Then, it almost always starts up fine after that. Sometimes I'll have to repeat the process; but it is usually fine. And then, sometimes everything just starts up fine. Once I'm in Windows, everything runs perfectly.
I have very little idea what is going, since it is not determanistically reproduceable. It does seem to have something to do with USB power not reaching all devices correctly on boot up, since; sometimes when I perform my restart on a failed boot - i get no response from my keyboard. I am fairly certain that my PSU is having no problems powering everything.
My motherboard is an Evga nForce 730i.
Intel 8800 E8500 Core2Duo
2 SATA drives
1 External WD drive
Belkin n52te keyboard
Logitech g15 keyboard
Logitech Mx518 mouse
I am not using any USB hubs, am not overclocking, and all my software drivers are up to date. My motherboard BIOS is at the most recent flashed version I could find.
Troubleshooting steps I have taken so far, is to try booting with different devices unplugged in different combinations (no DVD, no External HD, etc.) to see if an individual device was causing the issue. So far, the issue re-occurs regardless of which device is unplugged. With the exceptions of keyboard, mouse, and HDs.
Any help or others who have run into this issue would be appreciated!