Microsoft's top lawyer says it was perfectly in order to describe PCs as "Vista-capable" when they could only run restricted consumer versions of the operating systems.

Last week, a class-action lawsuit was brought against the software maker claiming it unfairly labelled some PCs ‘Windows Vista Capable’ ahead of the operating system's launch in January this year. When Vista arrived, these PCs could only run the most basic version of the operating system and did not support more advanced versions that offer some of the most heavily-promoted features such as Media Center facilities and advanced graphics.

"I actually don't think there have been a lot of problems that consumers have encountered although I think there are a few lawyers and law firms that have pursued an action that are presenting such a picture," said Brad Smith, a senior vice president at Microsoft and the company's general counsel, during a news conference at the Foreign Correspondents' Club of Japan in Tokyo.

"I actually feel good about the information that we provided," he said. Nonetheless, Microsoft has revised the information in its website outlining the requirements for ‘Vista Capable’.

The lawsuit, which was filed in the US District Court for the Western District of Washington, alleges that "a large number" of PCs that sported "Vista Capable" labels were only capable of running the Home Basic version of Vista. Smith disputed that claim.

"Most of the PCs are able to run the kinds of versions like our Home Premium version that have virtually all of the bells and whistles," he said. "Even the machines that are not able to run something like Home Premium are able to run a version that provides many if not most of the major advances that are important to consumers."

There is fairly wide gap between PCs that are ‘Vista Capable’ versus those that are ‘Premium Ready’, according to information on Microsoft's website.

The former requires a PC with a processor running at a clock speed of 800MHz or faster, 512MB of memory, and a DirectX 9-capable graphics processor. The latter calls for at least a 32-bit or 64-bit processor running at 1GHz, 1GB of memory, DirectX 9 graphics with a WDDM (Windows display driver model) driver, 128MB of graphics memory, and other requirements like a 40GB hard drive, DVD-ROM drive and Internet access.

The lawsuit seeks class action status and says the size of the class likely exceeds 10,000 people.

Read our definitive Windows Vista review.