Went to Discovery Channel Store today and found out they're overstaffed and have no place for me to work over Christmas. Crud. Maybe I won't work at all.
I did some looking and found that the beastly noises coming from Dad's computer were from the power supply fan, so I sent him out to buy a power supply and an 8cm fan, because I've never opened up a power supply before and wasn't sure if we could replace just the fan. He came back with a power supply and a 3.125" fan... I hate America. But anyway, we installed the fan okay in the end and taking apart the mini-tower proved to be more exciting than I'd anticipated. I have only one word of advice for anyone wanting to install their own power supply fan: if you must plug in your power supply for testing purposes while it's still open, plug the cord into the power supply before plugging the other end into the wall. Otherwise, you might forget what you're doing and hold the wrong part of inside of the power supply and shock the holy living shit out of yourself like I did. It may feel kinda interesting, but it will freak your mother out, especially when she still thinks you should have gone into education or creative writing.
But Dad's computer is okay again, quietly running Windows 95 at 166MHz like it should be. Ah, it feels good to have fixed something.