recently something odd keeps happening with my pc, as I go to shut the computer off i click shut down, then it goes through the shutdown process and as I hear the clicking off sound I usually do when my pc shuts off then the pc does a restart or something and boots up again....

Then upon bootup I get this weird error message saying the system was forced to shutdown or something, then I exit the error msg and go about my business playing videogames or w/e...and everything seems to be running okay...just occasionally this happens and after the error msg i can shut the pc off normally and it shuts off...its odd