Computer restarts after I press start Windows normally

[Fuzzy9001]

Ok so earlier today I had to force shut down computer because I couldn't wait for it too automatically shut down when I got back earlier and started it up it came up with start Windows normally I select it then it restarts and I do it again it takes me too the Windows starting screen and then I get another restart. After that in fear of my comp damaging the hard drive I force shut it down any suggestions on what could be causing this?