Mom turned on her emachine this morning and got to the password prompt on her Windows XP screen (with cursor blinking) and could not type anything in the box. Her keyboard lights were blinking (Num Lock, Caps Lock, Scroll Lock) but there was no response. It sounds like a hardware problem to me. Could it be her keyboard, or possibly her power supply? Please help... Thanks.

With the PC off, disconnect & reconnect the keyboard. When the PC is urned on, note when the keyboard lights START blinking. If the lights blink immediately, the problem is hardware because the software has not loaded yet. If the blinking waits until the XP screen appears, then suspect a software or firmware configuration issue. The keyboard can be replaced temporarily with a borrowed keyboard. It does not have to be the same type keyboard but must have the same connector on the cable as the original keyboard. While this sounds like a bad keyboard (typically caused by a coffee spill, etc), it could be a defective system board. Trying another keyboard would answer that question.