So I decided to try to fix my computer last night. I thought I'd fixed the weird losing time/eventually freezing often problem, but it hadn't totally gone away. So I went into safe mode and deleted every device I had. I figured Windows would get everything back just fine with its Plug 'n' Play magic. Three hours later, everything was fine again. :P
Unfortunately, the odd freezing problem remains. I'm thinking of maybe trying a Windows 2000 upgrade to see if a new OS would fix the problem magically. I don't know why it would work or even why this happened so suddenly, but it's worth a shot.