To fully protect your PC, anti-virus programs need to run all the time no matter what the computer is doing, but leaving a program running constantly can slow the computer down especially when it’s performing demanding tasks such as if you’re playing a game.

What caught our eye about the new Sunbelt Vipre anti-virus and anti-spyware software was the big yellow sticker on the box that says 'does not slow down your PC!'

We were pleased to find that the program lived up to its claim. We installed Vipre on our test PC and then fired up the recent game Call of Duty 4, noticing no obvious slow-down in the on-screen action. And once it had been installed it ran a thorough scan of our PC’s 120GB hard disk in a very respectable 30 minutes.

The initial installation could have been a little smoother, though. There is no printed manual supplied and the 100-page PDF manual that’s included on the CD is rather daunting.

We were also worried when the program’s setup wizard asked about technical details such as what proxy server we were using and requesting ‘user authentication’ settings, but these turned out not to be a problem. Still, the developers of Vipre could have done more to simplify the initial installation process for less-experienced users.

Fortunately things ran more smoothly once the program had been installed. The wizard allows users to schedule regular virus scans, and specify the email programs they use so that Vipre can check incoming emails for viruses and other threats (though it can’t monitor web-based email services such as Hotmail or Googlemail).

Our only complaint is that Vipre doesn’t offer a recovery disc option to start the computer in case a virus infection means it can’t load normally.

There is no firewall or spam killer but at just £30 a year Vipre is cheaper than many other similar programs so it’s worth considering if you don’t need those extra tools and you only have one computer (a further £20 covers all the computers in your home).