I'd watch a few YouTubes about canned air use to clean the vents and heatsinks of your PC. With that done you can get some canned air and clean your PC up a little.
My PC just made a noise like a police siren going off. It was definitely not coming from my speakers but from the desktop PC itself. Did an emergency reboot to stop it and it scared me pretty badly!
As I recall I had Ms word open, a paused Pc game called Pirates of the Burning Sea open and a bible program called e-sword.net open at the time the siren went off. And it was a siren sound, no beeps or anything like that!
Since I rebooted it's been fine. I'm at a loss to understand why my computer decided to give me a heart check, anyone know what's going on? Or what I can do to keep it from happening again? Thanks in advance for your thoughts.

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