Re: shot in the dark

Find the box inside the computer case where the power cord connects from the wall of the room to the computer. That's the power supply. The power cables that you plug into your motherboard and drives all come from the power supply.

It's a fairly simple part to replace. Unplug the old one from the wall and from all connections inside the case. Remove the screws on the back of the case and take the old one out. Put the new one into the case and screw it in. Plug the internal power cables into the motherboard, drives, etc. Plug the power supply into the wall. Turn on the system.

Here's a question: When you shut your system down (on purpose) does it turn off automatically, or do you still need to hit the power switch to turn it off? If it shuts off on it's own, you have an ATX power supply. If you have to hit the switch, it's probably an AT power supply, but might still be ATX.