Very often while playing Team Fortress 2, and no other game does this, it will crash my display driver and sometimes I have to restart it. But even more often it crashes my entire PC and requires a hard restart. When it crashes the last sound heard just loops and nothing I press or do does anything to stop it. My drivers are up to date, my gpu is not dead, I verified integrity of game cache, and some other small fixes I've seen, nothing worked. Note that if my gpu is overclocked it works fine in most games except ones that are not very GPU intensive like TF2 and other Source engine games, where it crashes the display driver really quickly. But all these crashes are happening without any overclock whatsoever and seem to happen randomly.
Thanks to those who respond with advice.
Thanks to those who respond with advice.