Computer owners who pay for top-of-the-range security software could be wasting their money, according to Which?

A report by the consumer watchdog found that free alternatives to popular security products such as Norton Anti-Virus and McAfee VirusScan work just as well as paid-for programs, and were on the whole just as easy to use.

The only drawback to free anti-virus and firewall programs, the report concluded, was that the user might have to look further for customer support services, and in some cases would have to download updates manually.

Security software typically costs between £30 to £50, depending on the brand, and the licence to use it must be renewed every year.

"If you're reasonably confident with your computer and are happy to look for support in places like forums, then free security software is a good way to go, and certainly saves a lot of money," Abigail Smith, head of research at Computing Which?, the magazine, said.

The report reviewed 15 free 'security suites' across four categories - anti-virus and anti-spyware, which protect against malicious programs, firewall, which acts as a barrier between the computer and the internet, and anti-spam, which filters inboxes for junk e-mail.

Five out of the 15 scored 5 stars - the top rating - for performance, and 11 scored 4 or 5 stars for ease of use. Among the most highly recommended were Avira, Avg, Avast!, and Checkpoint.

"You don't have to be any kind of computer wizard to use this software," Ms Smith said. "There may be a little bit of additional 'housekeeping', but many of the websites which offer them have good 'frequently asked questions' sections, and there are also forums where you can go and seek advice."

Symantec, which sells the Norton line of products, said that while there "certainly" was "good basic free software" available, it wasn't as comprehensive as the paid-for varieties.

"We have more than 40,000 sensors monitoring the newest threats on the network in more than 180 countries," a spokesman said. "The benefit of purchasing from one of the established manufacturers is that you also get the expertise, research and development infrastructure and experience."

McAfee, another established provider, said that the advantage of all-in-one packages was that customers didn't have to go to different sites for different types of product - as was the case with free software - and that updates were automatic.

Symantec had 26.5 per cent of the market for internet security products last year, according to Gartner, followed by McAfee (11.3 per cent) and Sophos (7 per cent).

BRAND/WHICH? RATING

ANTI-VIRUS

Avira - 92 per cent
AVG - 91 per cent
Avast! - 91 per cent

FIREWALL

Checkpoint ZoneAlarm - 94 per cent
Microsoft Vista - 64 per cent

ANTI-SPYWARE

Microsoft Defender - 80 per cent
Spybot Search and Destroy - 74 per cent
AVG - 60 per cent

ANTI-SPAM

0Spam.com - 56 per cent