Jason Garms, the architect and group program manager for Microsoft’s anti-malware programs, wrote in a blog that his team has started to prime the Windows Update software distribution channels with signatures for Windows Defender.

He added that Windows Server Update Services, server software that enterprises can already use to streamline patching on the corporate Windows network, will also be able to handle Defender signatures and updates.

The move to anti-spyware as, as Garms blogged, a system service, has been on the cards since January, when Microsoft started making its Malicious Software Removal Tool available via Windows Update.

It became even more obvious that this would be the channel for AntiSpyware in October, when Microsoft confirmed that it plans to bundle Defender, then known as AntiSpyware, with Windows Vista, the next version of the client operating system.

But having Defender promoted via Windows Update, which hundreds of millions of Windows users access every month on Patch Tuesday, will likely increase the distribution of the software before Vista is launched.

Other than the usual ‘it will expand the overall market’ line, Microsoft’s moves can’t be great news for pure-play anti-spyware vendors, which are already competing against anti-spyware features in antivirus products and face the prospect competing against Windows.

Garms blogged that Windows Update will be ready to support Defender updates when we ship the next beta of the software.

Microsoft has not said that it will bundle antivirus with Windows Vista, but Garms said that there is some technology crossover, saying Defender is applying to spyware threats all the great detection technology we use in our antivirus engine.

European Union competition regulators, which have previously taken a strong view on Microsoft bundling software with Windows, are already believed to be looking at the company’s security plans.