Frustrated with 3 Computers

Ok, first off, I'm getting extremely angry.

I'll make a list of the computers I have:

1) The first computer, it is a Windows, HP Computer, pretty old, Intel, everything works fine but the motherboard, because no matter what hard drive I use, it won't transfer any form of data. I've tried changing cables, everything, and I get nothing.

2) It's a Mac G3, pretty old as well, and it works flawlessly, but it's horribly slow, and I need the case removed, BUT there is a lock on the case, and I can't get inside of it. (I'm trying to make a computer without a case, for my own reasons I'll post later)

3) I've got a Mac G4, the most recent of the computers, pretty fast, but the CPU blew out on me. Everything else works fine.

Now, my question to you guys... I've gotta make a caseless computer, but I can't find the parts from these 3 computers to make an actual working computer. If I could get that lock off, it would work fine, but I can't get it off.

If you guys could help, I'd appreciate it.

Thanks.

That lock should use a generic key. The round kind with the slot on the end? Any key will fit.

when the hardware is 5 years old or older what do you expect