Every computer has fans which are cooling down your CPU, thousands of hours fans are working to blow air into your computer to cool it down. During this time a lot of dust is placing itself on your computer.
This can be a serious problem more for Desktop computers which can get a lot of dust inside. Dust is placing it self on every component, every scheme. This can really produce overheating, because dust is like a layer on computer parts and does not allow them to throw the head out.
In another circumstances like getting your computer from a cold environment to a hotter one or room temperature changes fast at a point. There can be an short circuit which can kill your computer.
Dust also is a problem for optical drivers, if you will not clean your computer, your optical drive will start to work bad, because also places itself on the laser writer head.
How to clean your computer from dust?
To clean your optical drive you can find in any computer store a Cleaning CD. A Cleaning CD is a special CD which has on it a very soft small brush, then on the CD you poor on a special liquid which comes with the CD, then you insert it into your CD/DVD – Drive and you run from the CD a small program which will spin the CD to clean it.
To clean your Desktop computer read our guide here: http://technozed.com/why-is-your-computer-slowing-down/