Windows Vista, the next version of Windows which will succeed from XP, will introduce important changes to the way the OS runs, as well as including Windows Defender, an anti-spyware tool. John Pescatore, an analyst with Gartner, postulates that this will lead to a decline in the threat of spyware, as Vista gets adopted; a significant number of the attack vectors that spyware authors use today have been disallowed in this new OS. This is good news for users, but what affect will this have on Microsoft's anti-spyware rivals?

While this may be good news for buyers of Vista, it is not for anyone who makes a living from selling anti-spyware software. The worldwide market has boomed recently, reaching $97m in revenue in 2004, up 240.4 per cent from a year earlier, according to IDC. However, companies such as Sunbelt Software and Webroot Software are in for tough times, analysts said.

Yankee Group analyst Andrew Jaquith said: "The aftermarket for Windows anti-spyware is going to dry up almost completely. Windows Defender is going to become the default anti-spyware engine, certainly for most consumers that have Vista machines."