Yesterday, I had to flip off one of the circuit breakers for the repairman. Unfortunately, the breaker panel wasn't well labeled, so I had to figure out which one it was through trial and error. Which meant the computers lost power.

When they came back on again, Karen's machine had no video. As her monitor worked on my machine, and re-seating her video card had no effect, it was apparent that her video card was bad. So I bought my machine a new video card.

(That's the way it works in our household; new parts go into my machine, the parts they replace go into Karen's. Which works out well for both of us; my computer usage requires gobs of memory and raw number-crunching power, while Karen's doesn't. Not that her computer is a pathetic ancient heap; she currently has a 1.4 GHz Athlon with 512 MB of memory. And my old video card was only a couple of months old anyway.)

Anyway, I stuck the new video card and the memory into my machine, closed the case and screwed it together, and...

Nothing.

Lee's First Law of Computer Upgrade and Repair: Closing and screwing shut the case before testing to see if the machine will boot guarantees that you will have to open it back up again immediately.

The video card had apparently not been seated completely. So once that was rectified, my computer hummed along merrily. Except for the fact that the video drivers on the CD-ROM weren't signed, so Windows XP complained mightily that installing them would call forth rains of frogs, cause three-headed goats to be born, and afflict me with terminal halitosis. I would, obviously, have to download them from the Net; however, Karen's machine is set up as the Internet gateway.

So I put my old video card in Karen's machine, turned it on, and...

Nothing.

Arrrgh. So I started pulling things out of her machine, until just the video card remained. Still nothing. I double-checked to make sure the video card was seated completely. Still nothing. I pulled out the power supply and tried a different one. Still nothing. So I pulled out the motherboard, stuck it on non-conductive foam, hooked up the power supply and the video card, and turned it on. And it worked.

I put the motherboard back into the case. It worked. I hooked up the drives. It worked. I secured the power supply back into the case. It worked. I put all the other peripheral cards in. It worked. I screwed it all together. It worked. Just for grits and shiggles, I hooked together the bad video card, an older motherboard I had lying around, and the power supply I'd just taken out of her machine. It worked.

Lee's Second Law of Computer Upgrade and Repair: Computers are capricious, malevolent bastards that exist solely to play mind games with humans.