Wife's PC

I disconnected both hard drives so that i could use the machine to copy stuff off of my hard drives. That went well, and I should mention that I installed XP on one of those.

Disconnected my drives, and reconnected the original ones.

Doesn't boot up.

Even the video isn't working. It looks like a very bitty 2-colour video which you can barely make out. I can get into the BIOS, barely read it, but that's it. Nothing.

What have I done?

Memory.

I tried to plug in some better memory sticks.

Fixed.