As the name suggests, Onecare is one of the growing breed of software products that offer what they call 'total' protection for your computer.

In addition to containing firewall and anti-virus components, Onecare has a spyware killer and a backup program, as well as a system cleaner that will rid your PC of junk files, and a tune-up utility for tweaking it to top performance.

The annual subscription allows it to be used on three computers in the home, and it can be used on both Windows XP and Vista. We tested it with Vista – it's more at home with the newer operating system, and some of the components are built on things that already exist in Vista, such as the Defender anti-spyware tool.

Setup was quite easy, although it insisted on first connecting to the internet and downloading updates, which added several minutes to the process. It was also compulsory to restart the computer once it had finished, although this is common in security programs.

On rebooting it presented us with a box requesting that we log in to the online service. You need to sign in with a Windows Live ID (what used to be called a Microsoft Passport) - if you have one of those or a Hotmail address it's easy, otherwise the process of creating one is not onerous.

It then asks the user to go online and buy a subscription - if you've bought a boxed copy rather than downloading it, there's a button on the same web page for this. Tap in the code in the box and it will link the software installed on the computer with your own Windows account.

Once that was done, the program prompted us to update the Windows installation - it keeps an eye on current updates, so you'll be prompted if there's something important you need to install. It also prompted us to make a backup and to turn on the Phishing Filter.

The software worked unobtrusively in the background with few alerts to bother the user, except when necessary (for instance, you get a firewall alert when a new program tries to access the internet).

The Onecare icon that appears in the Notification Area changes colour depending on how well the system is protected – to get it to go green it's necessary to follow all the steps listed in the main program window, such as setting up a backup regime.

We found this tricky, because Onecare refused to work with a couple of the external disks we tried. It worked eventually, though, at which point we were given the (literal) green light. The new version of Onecare adds features such as online backup for photos, although this costs a hefty £39 a year on top of the price of the main product.

Administering the computer and changing settings is easy, but Onecare cleverly makes it hard to change anything by mistake. It puts the three computers in your house on which Onecare is loaded (if you choose to do so) in what's called the Onecare Circle, which means you can administer any of them from the master computer (so you don't need to physically use a child's computer to change their settings). It also adds clever abilities such as printer sharing to all the computers in the circle (and backing up all the PCs in the circle).

Vista compatible: Yes