[rampancy]

Thanks for the tip, Taskiss - Sears in Canada doesn't seem to carry that, but Canadian Tire has a set of similar products. I was thinking about bits of metal getting all over the motherboard too, so I was planning on getting some plastic drop sheeting to put over the rest of the computer.

Anyway, so I tried to get that damned screw out again, just to see if I could do it without resorting to fancy tools - I was actually able to get it out by gripping the head with a set of pliers. I'm thankful the screw wasn't wedged in any tighter. In any case, thanks for the suggestions!