My Computer Shuts Down Instead of Sleeping (and does other weird things)

[AuthenticGeek]

So my custom built computer has been acting weird this week. If I leave the computer alone for ten minutes, the display turns off (which is normal), but then the screen turns back on. When I try to use it it won't play YouTube Videos or any media files. I try to play a song on my computer windows says it cannot play it. Rebooting the computer will solve the current problem, but I left the computer alone to see if it will go to sleep. I leave it alone for awhile and come back, the computer has shut off. I turn it back on, it tries to post (and the BIOS loading screen looks a bit glitched out) then it BSOD then restarts and then it boots normally. If I leave the computer alone for awhile, this whole process repeats. Any ideas what the issue might be?

 

[notlim981]

This could be either a bad overclock of a bad PSU. If you did any overclock in your build, get in the BIOS, load the default settings and see how it behaves.

 

[AuthenticGeek]

This could be either a bad overclock of a bad PSU. If you did any overclock in your build, get in the BIOS, load the default settings and see how it behaves.

I've loaded the default settings in BIOS, flashed it with an update, and reinstalled Windows. It no longer seems to shut down by itself, but it still has issues playing media files from the internet such as YouTube or directly off the hard drive when you leave the computer alone for awhile and come back to it. .