Possible Power Supply issue. Need help.

I have had an HP Pavilion A375C that decided this morning to stop working. When I got up, I noticed the computer wasn't on. I tried to start it but nothing happend I checked the surge suppressor and it looked okay. I shut itf off then pushed the reset button and this allowed the computer to start up. I walked away since it will take a while to boot up. I noticed it completed the POST and started to load Windows then switched to CHKDSK to run a check. I let it run assuming that it would boot in to windows when it was done.

When I came back the computer was off. I checked the switch again and it started up. I decided to verify that the surge suppressor wasn't the issue. I plugged the computer into the wall socket by passing the suppressor. The computer started and went into CHKDSK again. It finished the initial check and was about half way to through the second check when it rebooted. It chugged and groaned and eventuall shut off again. When you push the button it wouldn't start. I unpluged the power cable and replugged it back in and it went through the whole process again with the same results.

I replaced the power cable and still got the same results. I am running Windowss XP with the latest SP, I believe it's 3. I can't get to safe mode to by pass the chkdsk.

I believe it's not the suppressor nor a bad cable, I guess it could be a corrupt hard drive but normally I'd get a "cannot find NT.LDR or another error dealing with the Krnl.

How can I check this out? It's an old computer but it has two IDE hard drives that store a lot of files for me. Will I be able to move these to a newer computer with ASATA drives? What issues would this present?