No matter how cheap computers have become to buy, it's still much cheaper to clean out your hard drive and upgrade your PC components, and doing so isn't some sort of black art where you need to don a pair of industrial gloves and a hard hat. Simple upgrades don't require any specialist knowledge and they will only take a few minutes to achieve.

You don't even need to spend anything if your PC is already up to scratch. A few simple tweaks in Windows Vista can give a computer that's not been regularly maintained a real speed kick. It's like taking your car to the garage, getting it serviced, and afterwards noticing how much zippier it feels.

If you bought your computer a year ago, and you've decided that opening up your PC case and swapping the innards isn't the route you'd like to take, you can still make it a lot quicker. But before you can really start to eke more from your PC, you've got to do some basic housekeeping.

The likelihood is that since you bought your PC, you've downloaded all kinds of things, filled your hard drive to the brim and haven't once given it a thorough cleaning. No matter how good your PC is on the inside, if it's got junk clogging up the operating system, it'll suffer.

Free up hard drive space

The very first thing to do is check whether your hard drive has enough free space. If it's completely full, your PC will crawl. The general rule of thumb is to leave at least 15-20 per cent of your hard drive empty, so if you have a 500GB hard drive, you should keep at least 60-70GB of space free.

Start by removing any installed programs that you no longer use. You can do this by going to Start > Control Panel > Programs > Uninstall a program. Click any programs you want to remove, and select Uninstall/Change.

If you're struggling to find those last few gigabytes, then it's worth doing a disk cleanup. This will get rid of all the unnecessary files that have been left on your PC after you've been surfing the web or when a program has crashed. Windows Vista comes with a pretty good tool for cleaning things up as standard (Start > Disk Cleanup) but there are other programs available that do a more thorough job.

CCleaner scans your hard drive and automatically removes anything you don't need. Depending on how old your PC is, you can expect to gain, at the very least, one or two gigabytes of extra space.

If you're willing to go one step further, you could consider deleting your System Restore points, as each of these take up a lot of space. You obviously want a recent one, but the rest aren't really needed. To do this, you need to open the Disk Cleanup utility, and when prompted select Choose to clean files from all users of this computer. Then, in the More Options tab, click Clean up underneath the System Restore and Shadow Copies option.

Once you've had a good tidy, now's a great time to give your hard drive a re-jigging. If your hard drive is fragmented, it will take much longer to open files or programs. Click Start, type disk defragmenter and then click Defragment now.

Speed up boot times

One of the most common gripes with Windows Vista is the time it takes to start up when you turn on the PC. One of the biggest factors in a lengthy start-up time is the number of programs that load during this time. You can easily speed up your start-up time by removing anything you don't need.

Click Start and type msconfig. In the System Configuration window that appears, select the Startup tab. This will show you all the programs that are opening when you turn on your PC. Clear the check box of each program you want to remove from the startup and click Apply.

You can improve the overall speed of Windows Vista by removing the eye-candy that makes it look so nice: Windows Aero. This is especially pertinent to those who have slow graphics cards – the kind you get with basic desktop PCs and laptops. Turning it off is easy – right-click the desktop and choose Properties > Aero off. If you turn off the Windows Sidebar as well, you'll get even better performance.

Re-install Vista

If none of these changes has an impact on the speed of your PC, your options from here-on are pretty limited.

The only way you're really going to get a faster PC is to reformat your hard drive and reinstall Windows Vista. This will put your PC back to its original state.

Before you go ahead and do this, make a note of all the programs you've installed so you can easily reinstall them again, and make sure you have driver CDs of your hardware to hand. If you don't, download them from the appropriate websites. Most important of all is to back up all your files onto an external hard drive, making sure to copy across your precious pictures, documents, and emails.

Once your PC is ready to be brought back from the dead, get your Windows Vista installation disc (or the recovery disk included with your PC, if you bought it from a manufacturer), restart your computer and insert the disk once you start booting again. You'll then be given the option to reinstall Windows Vista. Choose this option, and when prompted, select the option to format your hard drive, then continue to reinstall Windows Vista. Enjoy your faster PC!