From today home users will be able to get hold of Microsoft's long-awaited update for Windows XP. The version of the SP2 security update for the Home Edition of XP has become available via its auto-update service.
However, users of XP Professional Edition must wait until 25 August to get a version intended for them. Users who prefer to get a CD of the key update may have to wait a few weeks because the software was only recently released to disc manufacturers.
Unprotected PCs hit by viruses in minutes
Network worms can get onto a PC within minutes of connecting to the internet, according to security researchers at the Sans Institute.
The "survival time" for an unpatched PC connected to the internet averaged 20 minutes in 2004, compared to 40 minutes the year before. Users of broadband, or poorly secured public networks, would be infected much more quickly, in under 10 minutes after connecting in some cases.
"The main issue here is that the time to download critical patches will exceed this survival time," the researchers said.
Security companies are also monitoring the state of play, and are even more pessimistic. Symantec estimates that it could take seconds rather than minutes to lose control of an unpatched PC.