I tried to shut down my computer. It was taking a long time to do so, (orange light was on for a long time but the screen was black), so I powered it off.
When I tried to turn it back on, the Windows logo appeared with the circling dots. It continued indefinitely.
After two attempts, the "repair your computer" title appeared. Then it "diagnosed" my computer but found no errors. I pressed continue to startup, but the screen just turned black. I restarted the computer several times, but the same thing happened.
So I tried to boot the setup CD. Again the circling dots appeared, but then it got stuck at a purple screen.
After trying to boot it several times with the startup CD, after the dots the screen now turns black. Then after 20 minutes, it just turns off by itself.
Does anyone know what is causing this?
I talked to a Microsoft support agent. They said that the CD might be corrupted. That's probably not true, because I tried with two copies, a new one that I created for this task, and another that worked in the past on a different computer.
What can I do to repair my computer?