Regularly open your PC and remove dust buildup from the CPU and while you are at it the PSU
 

Computers operate on such low voltages that static build up from dust will interfere with its operation.
It is so common that many a computer upgrade as been because of failure to clean out the dust. 
Many "Sonar crashed my PC" statements are false and the result of dust build up.
It can cause the sudden switch off and even the dreaded blue screen and the failure to boot up  and stall is a tell tale sign you have dust.
 
At least every 6 months detach the CPU fan. This can be the heatsink on modern PCs and physically remove the dust. (check manual  but either screws or clips. If you are uncertain, get your local computer store to do it.) 
 
 
 

BJN
 
At least every 6 months detach the CPU fan. This can be the heatsink on modern PCs and physically remove the dust. (check manual  but either screws or clips. If you are uncertain, get your local computer store to do it.) 
 
 
 

This seems a bit extreme to me, though YMMV. I've built quite a few PCs for my audio use over the years and, while dust buildup is occasionally an issue, I've found that the computer becomes obsolete long before the dust becomes problematic.

Somebody with more in-depth technical knowledge/experience may correct me, but routinely removing the heatsink seems a bit dangerous to me; the paste interfacing the heatsink and the CPU forms a nice, tight seal over time, encouraging efficient thermal connectivity to allow optimal cooling. I'd think removing the heatsink would disrupt this process. Seems like a pretty tight space for dust to be getting into, anyhow.

Maybe I've just been fortunate enough to live in a pretty dustless environment. Not too dusty here in Philadelphia. :]

fif4lifefif

BJN
 
At least every 6 months detach the CPU fan. This can be the heatsink on modern PCs and physically remove the dust. (check manual  but either screws or clips. If you are uncertain, get your local computer store to do it.) 
 
 
 

This seems a bit extreme to me, though YMMV. I've built quite a few PCs for my audio use over the years and, while dust buildup is occasionally an issue, I've found that the computer becomes obsolete long before the dust becomes problematic.

+1. My internet PC has been around for as long as Vista has been out and it still runs pretty darn good. I've used compressed air to blow the dust out of it from time to time but I'd never consider removing the CPU fan.

I've built quite a few boxes in my time, fixed countless others. Dust on the CPU fan, and the power supply is the first thing I look for. In older homes down here in the south dust is bad. So it's not out the ordinary. However, I rarely remove the fan unless I have to.
 
 

Okay fair enough.
PC sure are obsolete quick and there are those who like the latest especially gamers.
With audio I like my PC to last as long as possible.
I have used the vac with attachment on the fan after about 6 months. A year later the fan has to come off and nowadays that means the heatsink. DO NOT CLEAN OFF THE CONDUCTIVE PASTE. and you'll be right.
The dust cakes on and you'll needs an old toothbrush to remove the crud between the fins.
The compressed air is a good idea geo. I can see that being better than a vac attachment.

Vacuum attachment sounds like more fun, though.

I recommend a yearly "blow-out" to myself and my clients.
 
I have replaced 2 power supplies I know failed from dust accumulation. One on a shop floor had exploded capacitors. And I have serviced 3 laptops that would not function because of dust and debris blocking fan vents.
 
No doubt some of the dead motherboards I have encountered became so because of non-vented heat.
 
The worst I have seen was from an apartment kept immaculate, wood floors, everything in its perfect place. The computer had been in place/use for about 3 years when I was contacted to help with a viri thang.  I figger it was mostly because the machine was near a return air vent.
 
I use a small paint compressor with a squirty nossle.
 
There have been times when I had to remove the heatsink to clean the fan with a brush. Prolly a high humidity space and the dust got stuck to the fan blades.
 
Always, the first step when working on a computer is to scan for and fix file system errors.
 
During a first visit I also inspect the innards for dust, loose cables,...
 
Know of a guy who started having computer crashes.  He reinstalled the OS 6 times before he discovered the damage done to a disk cable by a mouse.
 
In the beginning I had some trouble with loose SATA cables. Got some with clips. Fix the hardware first and the software will follow.

BJN
DO NOT CLEAN OFF THE CONDUCTIVE PASTE. and you'll be right.

The thermal paste dries slowly over time; so if that interface is EVER broken, it actually should be cleaned off and have new thermal paste applied. That paste is inexpensive, and when it begins to dry it does not create the same seal as it did when it was first done.

BJN
...A year later the fan has to come off and nowadays that means the heatsink. DO NOT CLEAN OFF THE CONDUCTIVE PASTE. and you'll be right...

Removing the heatsink and not cleaning off the thermal paste sounds like bad advice to me. I would say there is no reason to detach a heatsick from a CPU unless you are replacing it will a new one. And if you do remove it (as mettalus said) clean it off thoroughly before applying some fresh paste (or alternative conductor).

how do you know when it's your RAM getting taxed rather than your CPU?
 
 
 
anyways....my noob recipe for success (that I am learning the hard way):
 
-Take the time to understand the optimal file/folder structure before installing your DAW and other plugins.  things will run smoother and your workflow will improve when everything is in the proper place.  this is an area where you really HAVE to get it right the first time - or else you will likely deal with permanent misplacements that can only be corrected by reinstalling (which can be a pain depending on your arsenal)