Cleanliness is next to ....

I have worked on a few desktop system recently that had one major thing in common.

  They were filthy!
The above part is the base of a heatsink-fan combination, which helps to pull heat from a component (in this case the processor) and keep it from overheating.  (imagine a small fan mounted on top of this part to help move air).  All this dust is kind of like a layer of insulation, and keeps air (and heat) from moving freely.
Cases can also suffer from dust infiltration. A standard PC tower may have as many as 4-5 fans, but it may only have 1-2 intake and exhaust ports to move air through the tower. (Laptops are typically worse, they may only have one main air path, which is intended to cool the entire unit.  A block along this path will dramatically reduce any cooling effort, and temperatures will rise..

Falcon Northwest is well-known for making excellent computers, mostly in the high-end gaming niche, and they demand top quality designs for their PC's because they are frequently run at higher than stock speeds (over-clocked)
So, how do you keep it clean?

When is it time to upgrade?

This is a question I am often asked, and it is most often during the months preceding Christmas.  The answer is not as complex as you might think, and requires only a few questions to be answered.

1. How do you use your computer?
2. Are you online with it?
3. Is there important information on it?
4. Are you satisfied with its performance?
5. Are there things you would like to do (but can't?)

The first question is pretty self-explanatory, but what you use it for should be of worth to you (what value it provides to you as a consumer)
The second question is important simply because older Operating Systems (OS) like Windows 2000, Me, or even 98 are no longer secure online.  Note: Even if you are satisfied with your computer's performance, you should consider an upgrade if you are using anything older that Win XP.  This product is still supported by MicroSoft (MS), (meaning that security updates, etc. are still available), and so it's still safe to use.
The third question is important because the main storage of a computer, the hard drive, is a mechanical part.  It is subject to failure, and may or may not give warning signs (like a scratching or clicking sounds, repeated startup failures) before it goes out.  A catastrophic failure will make data recovery difficult (read: expensive) if not impossible.
The fourth is important because newer machines vs. ones with Vista and XP installed are more capable, have faster processors, more memory, as well as having a faster OS to run.
The last is a good question because many times people don't consider what they want to do when they buy a computer, and some of these are difficult to change once you take it home.
 
If it is time to upgrade, apply this last question to your new purchase as well.  Want to play WoW? (World of Warcraft)  Spend a few bucks more and get a gaming-level graphics card.  Are you interested in digital photography? Get a nice big hard drive (and an external one for backing up photos).  Do you want to make and distribute home movies and such?  Make sure you have plenty of RAM (memory), a DVD burner, and a program for recording home movies.

These are things to think about, but taking the time to access your needs will lead to a happier computing experience, and may prevent a purchase that you really don't need.
Happy Holidays!