Windows chief Jim Allchin has clarified recent comments about Windows Vista security, stressing that the new operating system does require antivirus software.

"I want to be clear that most users will use some form of antivirus software, and that will be appropriate for their scenarios," Allchin wrote on the Windows Vista blog. 

Microsoft's co-president of platform and services responded to media reports last week quoting him as saying that Vista's enhanced security meant that it did not need antivirus software. 

Allchin claimed that his remarks were taken out of context. "I made a comment about how attacks on the internet are getting more and more sophisticated, and some of the security features in Windows Vista really help our customers," he said.

"This somehow morphed into people thinking I said customers should not use antivirus software with Windows Vista."

The intended point, according to Allchin, was that in certain situations Vista would provide much better security for users.

Initial reports stemmed from a comment Allchin made during a conference call last week, when Microsoft announced that Windows Vista had been released to manufacturing and would be launched to consumers on 30 January. 

Allchin was talking about his home computer, on which his seven year-old son runs Vista without antivirus software.

"Even if there is a remote exploit on one machine, and a worm tries to jump from one machine to another, the probability of that actually succeeding is very small," Allchin was quoted as saying.

"My seven year-old runs Windows Vista and, honestly, he doesn't have an antivirus system on his machine."

Allchin also said that the machine used strict parental controls that limit access, restricting his son from downloading any files or receiving emails and instant messages.

The computer was also configured to limit internet access to a list of pre-approved sites.

"The point I had been trying to make (albeit unclearly) is that Windows Vista includes new security features that can dramatically help improve our customers' security for certain situations," he said.

Allchin recommends that users install antivirus software on their Vista machines, and that the example he listed was an extreme and very specific situation.