Computer Restarts While Using Cubase (recording Program)?

The problem is that the computer all of a sudden restarts for, according to me, no reason. It allways happen when I use Cubase (recording program) so that should contribute to that the computer restarts but it's not that the computer gets slow or anything because everything works and then all of a sudden it restarts and I lose all my work(if I don't remember to save).

My first thought was that the computer gets overheated or something but it doesn't seems to be that way either since the computer restarts and not turns off, if you see what I mean. Of previous experience I know that the computer usually turns off when it get's overheated (to cool down) and then after a while you can start it again, but the weird part this time is that it restarts directly.