Vista's repair DVD didn't detect any problems. Scandisk didn't detect anything, either. So I decided I'd try reinstalling. Worked for two reboots, and then it froze on the third one. Maybe some hardware components were the problem. I took out a wireless card and sound card I don't use anymore, and it worked once, but then no more.
So then I decided to install Vista on another disk, assuming the first disk was busted. Worked for a few times, and then it locked up. Okay, maybe it was something else on the IDE chain - I removed every IDE device, including CD drives, and unplugged all USB devices, and still - even after running on a disk I had put inside the computer just to install Vista, it would still hang after a few initial reboots.
Safe mode works most of the time. I just don't know what in safe mode makes it work, while booting up normally doesn't.
So I'm lost. I don't know what's causing the problem. If it's nothing IDE-related, and it's not the disk that's in there, then the only things I can think of are RAM (which I memtested), my video card (which I uninstalled drivers for to disable video acceleration - no luck), or my motherboard. No idea.
This really sucks. I've always been able to pinpoint the problem, but I'm really out of luck this time. I don't know what to do. I don't want to buy new RAM or a new motherboard because they might be perfectly fine. Maybe I should just install Ubuntu on my computer and say farewell to my days as a Windows user (and as a computer gamer and web designer - HAHA FAT CHANCE) forever?