Why is my computer shutting down with a loud beep?

Something inside is calling for help. (rim shot)



Seriously, though, this is common when the system is overheating or if a component is drawing the incorrect amount of power.

It's not unheard of for addon video cards to be connected improperly.

If the Power Supply Unit (PSU) is starting to fail, it could be allowing the fans to operate poorly and overheat the machine.

It could be global warming.

Question: is it beeping when you shut it down, or is it shutting itself down?