Anti-virus companies such as Symantec employ large teams to monitor new viruses and other types of malware as they appear on the Internet.

However, Symantec says the virus threat has now reached the point at which it’s almost impossible to keep up with the thousands of new viruses that appear every day.

So, for its Norton Internet Security 2010 suite, the company has developed a new system called Quorum.

In effect, this is a huge database compiled using information drawn from the PCs of millions of people who already use Norton software

This information is provided on a voluntary opt-in basis, so users don’t have to provide any information if they don’t want to.

Whenever you download a file from the Internet, or open an email attachment or load a file from anywhere else, Norton 2010 checks the Quorum database to see if the same file has been found on any other users’ PCs, and whether or not the file has caused any known problems.

If the file has a bad ‘reputation’ on the Quorum database then the security software will automatically attempt to remove the file before it can do any harm.

If there is no record of a particular file on Quorum then it can use another new feature called Insight to analyse the effect the file has on the computer.

The software can remove files that appear to be slowing the computer down or taking up large amounts of memory.

And to avoid affecting the computer’s performance, Norton 2010 uses less memory for itself – just 10Mb – and can scan the computer’s hard disk more quickly to ensure it doesn’t slow you down while you are trying to work.

The Quorum system may take a little while to prove its worth, but Norton 2010 ran very efficiently on our test PC. Its quick scan took just a few seconds to run and managed to pick up a few worrying cookies that were attempting to store information about our web browsing habits.

As with most modern security software the £50 price includes a licence for protecting three separate computers, making it good for families or small businesses that need to protect all their computers.