Despite some concerns before the final version, most players in the anti-virus industry have come out in support for Microsoft's claim that Vista will be the most secure operating system it has ever released.

Speaking to tech.co.uk, though, AVG 's global security strategist, Larry Bridwell, was keen to point out that "most secure does not mean totally secure, users will still need a third party, multi-layered approach to protection."

One potential weakness in Vista he pointed out is the danger of malicious code arriving through Desktop Sidebar gadgets - a fear first raised last December . Because each gadget is a self-contained desktop application, once installed they are exempt from the User Access Control (UAC) alerts which are designed to stop malware secreting itself on a PC.

When first installed, they'll be queried by the system as any new executable is, but a subsequent update could download malicious code to the calculator you installed last week without Windows' knowledge. Hence the need, argues Bridwell, for keeping up that subscription to your favourite anti-virus software package.

Bridwell was keen to praise Microsoft for its work in combating malware - especially at the industry-wide level where it has hosted conferences and news services for sharing information about new threats since 1997.

But he also pointed out that although the new operating system is safer than XP, it's still vulnerable to somewhere between 25 and 40 per cent of malware currently in the wild.

While Sidebar gadgets are a potentially new form of conduit for virus writers, the fastest growing threat apparently comes from webpages containing virus transmitting code that infects visitors to a site, often without the site owner's knowledge. These "could do for browsing what spam has done for email," he told us.