I am running Windows 2000 Professional. I just installed Service Pack 4 and now it won't boot.

Different Boot Modes

• Normal Mode: Freezes during splash screen at 11 or 12 bars on the load bar.
• Safe Mode: Freezes a little bit after text-based loading bar fills up all the way.
• Boot Log: Freezes in the same way. Creates no log whatsoever. In fact no matter what I've tried I have not been able to look at a single bootup system file name via any method.
• "Debug Mode": Computer boots fine. I don't know why this is called "Debug Mode", because it seems like a normal bootup to me.

While running in "Debug Mode":

• If I try to run Warcraft 3 it completely freezes during the splash screen. Can't Ctrl-Alt-Del, can't move the mouse. Immobile mouse cursor displayed on screen. I already tried re-installing Warcraft 3. Changing the video hardware acceleration settings has no effect, even at "none". Warcraft 3 ran fine before SP4.
• Quake 3 runs fine.
• iTunes runs fine. iTunes would not run before SP4, because it requires SP4.
• The internet, etc., etc. seems to work fine.

The attached pic shows everything under Settings => Control Panel => System => Hardware => Device Manager. The SiS devices are all onboard motherboard devices. My floppy drive and sound haven't been working for the longest time, and I haven't really cared. I want to stretch out the life of this old computer for schoolwork purposes until I graduate and build a better one. It still seems to work for that purpose, albeit with the need to press F8 at every bootup, but it would be nice if I could play the one major game I have. Amusingly enough, my iPod holds more than my hard drive, and I have the iPod set to disk mode. So a backup would be really easy to do. I do not have the original windows CD any more. If I did, I'd just backup and reinstall.

Any ideas on fixes?