It does still happen after a clean boot following your instructions, but I've just discovered that it does NOT happen in safe mode. So, I'm going to try updating every driver I've got. Edit: Well, the problem seems to be fixed now. I never did update any drivers, but kept messing with startup options instead. I got it to the point where windows wouldn't load, instead saying "bootmgr is missing , press ctrl+alt+del to restart" I played around with the bios settings for a while trying to fix that, including resetting them to default, then I downloaded a win7 recovery disk and did a startup restore and windows loaded again. Now after all that the problem seems to be fixed. I'm not sure if the startup restore or the bios changes fixed it or if it was something I did while breaking the windows startup procedure, but there you go.