You can definitely increase the life of your computer by getting the dust off the fans, cleaning the vents, and removing the crud from the CPU's heat sink fans.
Coincidentally, I just did a column on the topic. It's my Hassle-Free PC print column craftily entitled "Top Tips for a Cleaner, Faster Computer."
I always run out of space in my print column, so I wasn't able to talk about monitors, keyboards, or mice.
The Gang of Peripherals
My keyboard's always catching stuff -- dust, bread crumbs, and unidentifiable schmutz. As I suggested in the print column, I take it outside and blast it with a can of air. I have an Avant Stellar keyboard and it has four screws on the bottom. I remove the screws, carefully detach the keyboard from the case, and use the air can there, too. It's something you might want to try if you have the courage -- and the handyman skills. I also use a tissue and rubbing alcohol to remove the grime that builds up on the keys.
For more ideas, read Stan Miastkowski's excellent step-by-step, "Keep a Clean Keyboard".
I've never done it, but some readers recommend that if you spill beer -- or any other liquid -- on your keyboard, try popping it into the dishwasher
While I'm talking about keyboards, here's a good site to tuck away if you ever have trouble removing keys from your keyboard.
For monitors, you can watch the Digital Duo'[s "Keep Your Screen Clean" video.
Me? I follow the advice I found on Lenovo's ThinkPad site:
For even more tips, take a look at the Complete PC Preventive Maintenance Guide.
Finally, if you have a notebook, it could use cleaning, too. Read Jim Martin's "Spring Cleaning" for details.
