troubleshooting frequent restarts
About a week ago my PC started occasionally doing what I assume is the windows 10 equivalent of a blue screen of death and then restarting itself. The blue screen doesn't stay up long enough for me to read if there's any detailed error information, but I think all it says is "Windows has encountered a problem and needs to restart" and maybe a memory dump progress percentage that finishes in about a second. This morning it got worse, it restarted within a minute of logging in 3 or 4 times in a row until this time, where it has stayed stable. Perhaps coincidentally this is the first time I was able to close steam after logging on before it started downloading something today.
How should I go about troubleshooting what the problem is? The parts inside the case are all new except the power supply and the graphics card, which are many years old now, and the system has been running with no problems until now since I built it last summer. Is this perhaps a symptom of the power supply failing?