So when I started my computer this morning, it made a loud grinding noise so I immediately turned it off and check if any wires were blocking the fans. There were none so I started the computer again and the same grinding noise happened so I turned it off and removed the side to try to hear where the noise was coming from. The third time I started the computer, there was no grinding noise. Windows said there was a start up failure and I did the Windows start up repair thing which did a system restore. The computer booted up fine and there seemed to be no problems. I put the side back on and my first suspect was a hard drive failure. I did a HDD diag and it found no bad sectors. My only other guess is a fans' bearings being worn down or something but the noise hasn't come back yet so I can't check which fan it might be. Anyone have any idea what else might have caused this noise? I really hope that it's just a case fan that I can easily replace but knowing my luck, it won't be that simple.