Turn off your PC and unplug the power cable from the rear. If you want to be extra safe, unplug everything.
Move your computer to somewhere well ventilated if possible, or at least open a window or door to let fresh air into the room.
Remove the side panels and (if possible) the front panel of your case.
Use a lint-free cloth or can of compressed air to clean the dust from any dust filters, as well as any obvious collections in the base of the case.
Use a can of compressed air—we don't recommend trying to blow forcefully yourself—to clean the dust from any heatsinks like your CPU or graphics card cooler.
iosemus emus4u Happy Chick