If your computer's getting a bit long in the tooth, and its performance leaves a little to be desired, then PC World would encourage you to take it down to your local store for its 50-point Healtcheck service.

It has been running the PC Healthcheck clinic for the past two years, but based on customer and technician feedback it has updated the service, beefing up the number of points to check from 38 to 50, and improving the way your PC is assessed.

A check costs £39.99, or £69.99 if the check is done at home or work, and is carried out by a technician, who PC World is at pains to stress is "not a salesman, and doesn't earn any commission".

The Healthcheck starts with a consultation with a technician, designed to find out what you use your computer for, for example do you use it to play games, surf the net or to manage and edit digital photos or footage. Once your PC’s most frequent uses are established, the technician installs the proprietary software that runs through the 50 points to ascertain whether your hardware and software is up to the job.

The service looks at issues such as whether your virus checker is up to date enough to keep your computer free from bugs. PC World has found that 20 percent of the PCs it has checked were infected with a virus, even if the owner had installed a virus checker, as these were not configured correctly or were out of date. It is currently offering Healthcheck customers the opportunity to upgrade to Norton Antivirus for £19.99, £10 less than the retail price.

The technician will also advise on issues such as installing a firewall, which is becoming more important as users shift to always-on broadband connections. If your ISP isn’t up to scratch then PC World will install a Freeserve service instead, but it won't recommend any other alternatives.

On the hardware side, the check covers all the parts of your PC, with graphical images to show how much RAM and hard drive capacity you are currently using, which illustrates whether there is a need to upgrade or not. If your hard drive is cluttered with unused applications and files, the Healthcheck includes a clear-out of all of these unncessary files, plus advice on how to keep your PC free from such junk in the future. PC World says that the emphasis is on "education", and showing users "how to get the most from their PCs".

If upgrades are recommended, all labour charges are included in the £39.99 Healthcheck fee, which works out as quite a saving since upgrades are normally charged at £24.00 for the first upgrade and £9.99 for any further additions. Of course you do still have to pay for the hardware, but PC World says that it plans to offer special deals on components on an ad hoc basis.

The final element of the check is a full valet of the PC, to remove any dust and detritus from inside the case, which if left to build up can cause problems.

The Healthcheck is available at PC World stores nationwide, although appointments are advised. To find your nearest PC World store call 08705 464464.