Help, severe computer rebooting problem

Here’s my problem:

I have a computer that will constantly reboot right after the window logo. Although it will randomly boot like regular. I can boot into safe mode perfectly and it seems to boot a bit more after running a system restore.

I just recently moved it into a new case and I thought that was the problem, just a simple overheating problem, but once I moved it back it still has the same problem.

However I can’t boot the windows installation cd to reformat it, it restarts just like windows would.

I have no clue what part of the computer it could be with such an odd problem and at the moment I dont have the money to buy a whole new set of parts.

Has anyone had a similar problem or have any clue how I could fix it?