Your computer is restarting while playing DOTC
This used to occur a lot on older computer’s, now not as much. But if it still does happen to you, then it is most probably a bad video driver. Find your video manufacturer’s website and download the latest drivers for your video card and update them.
Some instances of this problem also happen when the video card overheats. In this case you need to enter run the configuration utility of DOTC and lower your settings to favor performance rather than quality.