The final conclusion, it's not the power supply. We tried a new power supply and it didn't work.

What was the problem? We could never figure it out but we did confirm the PC is DOA. After EIGHT YEARS it was just it's time to die.

The goal was then to save the old hard drive and move the data over to the new PC. At first the piece of junk we bought at Best Buy didn't work! It connected through USB only. My friend said the better transfer devices use an external power supply. The second device worked and the data was saved!

This was the new PC I bought. It's up and running but I'm still learning Windows 10, liking it alright, but it's going to take time to reinstall 200 programs to replace what I had.

https://www.bestbuy.com/site/ibuypow...?skuId=6032004

The moral of the story, BACK UP YOUR HARD DRIVE or at least the important stuff. I have two external storage devices with plenty of space so if I'd backed everything up more recently I wouldn't have been in such a mess.