AVG Free is a firm Computeractive favourite but there are several paid-for versions as well. We took a look at AVG Professional plus firewall to see if it is worth the money.

The most important benefit over the free versions is much better support. AVG Professional plus Firewall will download updates as soon as they are made available; AVG Free will only check once a day.

It is also possible to email AVG directly for help with the software. Unlike many other security products, the support and updates are provided for two years from installing the software rather than one year.

The installation wizard includes checking for updates and creating rescue disks. It can only use floppy disks, something of a disappointment as floppy drives become rarer, and the system backup took six disks.

AVG Professional protects a PC from viruses in four ways. In addition to full scans, the AVG Resident Shield constantly runs in the background, scanning files as they are opened or saved and checking programs before they can run. Email is protected with specific plug-ins for Outlook, Eudora and The Bat email clients.

Other email programs are protected with the Personal Scanner. This worked with Mozilla Thunderbird, Incredimail and Opera without requiring any settings to be changed. Attachments from instant messaging software are also checked.

Viruses in emails are automatically moved to a safe area of the disk that AVG creates. The full scan and Resident Shield both offer the option of deleting the file outright or attempting to remove the infected part of the file.

When a virus had already infected our test computer, all AVG did was remove the virus file itself; it did not reverse some of the changes it had made to the computer. Some help was available online, however.

On installation, the firewall scans the computer for software that needs to connect to the internet, displaying the results in a list for you to make your selection. The firewall options are included in the main screen, and one of the benefits of buying this version is that there is only one program to update, saving time and confusion.