Computers are often compared to cars in terms of reliability and power.

There's some truth to the comparison, especially when it comes to the speed of technology development and price decreases, but with reliability, the common notion that the PC regularly lets us down is a little unfair. Most cars have a full service a couple of times a year, yet computer owners generally treat their machines with a little less respect.

A poorly maintained tool is bound to let you down some time or other, so why not treat your computer to a complete service, without the financial burden of third-party maintenance fees? Grab a soft brush and a can of compressed air and in five minutes you'll have a PC that's much fitter for the future.

1. Power supply

This converts mains electricity to the lower voltage, direct current that's used in the PC. It has its own fan that you can clean using compressed air. Don't think about opening a power supply up – it's unsafe to do so. If it's very dirty or noisy then consider replacing it.

2. Processor fan

This keeps the CPU running as cool as possible in conjunction with the heat sink that's directly below the fan. Dust can build up here, making the fan less efficient. So consider using an artist's brush to carefully clean it, catching the residue on some paper.

3. RAM

Ensure that all memory modules are properly in place. It's worth reseating them occasionally to combat chip creep. If your PC has less than 2GB RAM installed, consider upgrading. This shouldn't cost too much and can provide noticeable performance gains at this level.

4. Hard drive

Today's high-capacity hard drives can run very hot, so consider investing in a hard drive cooler. This is a unit that provides additional fan cooling for the hard disk and can extend hard drive life considerably. See some models at www.quietpc.com

5. Motherboard

This is the main circuit board holding the pieces of your computer together. Keep it dust free using a blast of compressed air. Make sure that no metal objects, including screws, touch it when the PC's powered on. Check that all cable connections are secure.

6. Case fan

Like the CPU fan, this fan ensures that your system is as cool as possible, by keeping fresh air circulating throughout the case. It, too, can become as grimy and inefficient, so take a soft brush to it and remember to catch the dust so it doesn't just land somewhere else in the case.