My computer turns off itself: What do I do?

Hello! :)

I have a problem with my computer.. For some reason, my computer shuts off itself and then I have to turn it back on in a few minutes. I'm starting to get worried about this, what can I do? What do I do? Please help me! If you have any soloution, may you comment below? Also, if you had this experience before, also comment.

Thank you all so much C:

By the way: I have a Windows 7.

Hey guys, it's me. Please help with this problem, I'm starting to worry and thinking it would get worse, like hacking..... Please help me! :((