Microsoft did a full court press on Tuesday to try to counter the EC's statements about antitrust concerns with Vista's security features, emphasizing the company's work with independent software vendors.

Speaking with InfoWorld, Toulouse, until recently program manager for Microsoft's Security Response Center (MSRC), explained the company's reasoning in adopting security features such as Patchguard, a feature on 64-bit versions of Vista that prevents applications from "patching," or modifying the Vista core processing center, or "kernel."

Patchguard was necessary to stop unauthorized applications and malicious programs from modifying the Vista kernel to take control of the operating system. Legitimate third party products, however, such as behavioral detection products, also need access to the kernel.

Symantec Corp. executives have complained that Microsoft is using its dominance of the operating system market and hard line stance on kernel patching to stifle competition, but Microsoft allows third parties to extend the Vista kernel using signed, kernel-mode drivers, Toulouse said.

Microsoft's security products, such as Windows Live OneCare and Forefront, don't get an inside track to Vista features, Toulouse said.