Help, computer keeps turning off and won't boot regularly.

Ok so at first my computer started giving me the disk won't boot error and I thought I fixed it. It kept happening, and while I ran scans by both avg and malwarebytes, I thought I had gotten ridden of all the viruses. The way I got it to turn on, is one time I got into safe mode and did scans. Then after that I had to start going to bios and changing to optimal settings, (Which seems to add a drive to the master 3 slot ) every single time I wanted it to work. Sometimes it would work, sometimes It would stop working, and then start again after countless tries. Now, it's starting to turn off maybe 5 minutes in, if I'm not very active, or for any random reason. Also it likes to turn off when I start up wow (initial 5 minute period as well). It's happened twice so far. I don't know what to do anymore. Can anyone help?

Either power supply is faulty or it's overheating.

Start by cleaning out your PC completely. Google guides on how to do it correctly.

Can you format the hard drive and reinstall windows?

Then you'll know if it's hardware or software.

If your computer is powering down randomly, that would point to the power supply.

If it's failng to see the hard drive, that would also point to the hard drive failing.

First thing you do is narrow it down

Format the hard drive and reinstall windows.

If the problem goes away then it was some kind of virus.

If it persists then you have a hardware problem.

Run memtest

Why do people always suggest formatting Windows for anything?

This. My money is on PS.

Have you checked the event viewer for the exact date and time it happened? This could help you detect if it was a power issue.

I'll look up how to clean it and do that. I have not checked the event viewer. & It's weird because it won't boot unless channel master 3 goes from none to (WDD or something like that. I'd need to get it in order to write it but I can't get it to do that right now. How do I check if it's the power supply? I don't want to reformat it because I have a lot of un organized data spread through both of the drives.

Because it's easy to bork a Windows install and it's the cheapest possible fix.

I once had a computer that kept rebooting, even replaced the PSU

Turned out to be network driver (of all things.)

Needless to say I was pretty shocked.

Back up your files first thing.

Does your computer reboot if you don't try to play anything?

Like if you just browse for a few hours, does it reboot?

Start it up in safe mode with networking, play with it for an hour, see if it reboots.

If nothing happens, chances are it's a software issue.