The EC is still evaluating the information Microsoft sent in August on the Vista security features and hasn't decided what additional guidance it will give Microsoft.

There were similarities between the EC's position on Vista's integrated security features and the Commission's ruling on Microsoft's bundling of the Windows Media Player, Todd said.

That dispute resulted in a '497 million (US$630 million) fine against Microsoft in March 2004 for anti-competitive practices. Todd acknowledged, however, that security features also had a unique status.

"There's an extra dimension with security products. If I have a computer without a media player, it's not the end of the world. But a computer without security countermeasures is in deep trouble," Todd said.

"Clearly we don't expect Microsoft to sell software that would be vulnerable to security problems," Todd said.