Restart. My computer keeps shutting out of windows. It will restart on its on saying that windows

Question

My computer keeps shutting out of windows. It will restart on its on saying that windows not reponding need to restart. It does it mainly after I exit out of something using the small "x" in the upper right hand conor. I did a complete system recovery per conpacq b/c that is what they recommeneded. It still has the same problem. Help Please