Cleaning out your computer is valuable if you want to protect your business investment and keep your environment quiet.  See this article for a full explanation.

Computers in clean environments can be cleaned out once a year.  Computers in hard-floor environments like manufacturing facilities, or high traffic areas may need to be cleaned more frequently.

1. Gather cleaning supplies.  You’ll want forced air (either from a can or a powered air compressor), some towels, a spray cleaner or isopropyl alcohol, Q-tips, and a broom/dustpan combo or a vacuum for cleanup afterwards.
2. Start by turning off and unplugging the computer from the wall and disconnecting any accessories.  On laptops, remove the battery.  Then move the computer to a location with a hard floor, or move outside.  There will be lots of dust flying as you clean.
3. Open the case and set any parts aside.
4. Using the can of air or air compressor, deliver very short bursts of air to force dust out of the case and onto the floor.  Be sure to blow out the power supply, heat sink, fans, and get underneath any cables.  BE CAREFUL OF THE FANS.  They are plastic and long bursts of air or bursts that are too close can snap off the blades.  Also blow out any vent holes in the case.
5. Once you stop seeing dust, you may touch up spots as needed using Q-tips and isopropyl alcohol.  Then replace the case parts, and if you’re indoors, sweep up any excess dust in the room.