system crash report

My computer just had a system crash. Time of the crash-the music app was opened but not playing, safari window had a couple tab plus a you tube window opened but not active. When I returned, there was a darkened screen with small message in red in the center which I was unable to read as the computer restarted. The crash report was sent to apple then console open with the contents of the crash was in code. What was stated in Crash Reports was WindowServer under Process Name. Nothing in Spin Reports. In Log Reports-launch.log was the only entry for this day, however Idid find listed a couple of weeks ago was flash player install manager.log which when doing a search ,was found in my external hd which I now deleted. In system log-too much to code to understand. My question is were there too many apps and open windows that would have caused this crash and how can I find out the root of this crash? This is the first crash in years and would like to not have a repeat. Any advise or info would be appreciated. Thanks.