Microsoft sued over Vista branding

Microsoft has come under attack for the way it advertises the Vista operating system.

The proposed class action suit -- filed in Seattle on behalf of PC buyer Dianne Kelley of Camano Island -- alleges that the company advertised systems as "Vista capable," when in fact the systems were not able to run Vista properly. The suit alleges that the marketing around Vista was designed to deliberately mislead potential customers.

The outcome hangs on the precise definition of the circumstances under which a machine is "Vista capable."

Microsoft has allowed PC vendors to put stickers on their systems saying that they are "Vista ready," when the system could run only Vista Home Basic, which does not allow many of the core features of Vista to run. The suit maintains that it was unreasonable of Microsoft to assume that every person to whom it was marketing Vista could understand the system requirements.

PCs need at least 512MB of RAM, a processor capable of operating at 800MHz or faster and a graphics processor that is DirectX 9-capable to be classified as "Vista capable." However, the suit alleges that it was not clear from Microsoft's advertising and marketing around Vista that while a system may be advertised as "capable," it may be incapable of running many of the advertised features of Vista, such as the Aero desktop.

According to the legal action, which was filed as a class action suit on Thursday, "consumers were falsely led to believe they would be upgraded to a dramatically new operating system bearing the key features marketed by Microsoft." In particular, the court action highlights Microsoft's "Express Upgrade" plan, which upgraded users from Windows XP to Vista Basic. This was an upgrade to Vista "in name only," the suit alleged, and "not the functionality."

Microsoft said it had made extensive efforts to inform buyers about the hardware resources needed to run Vista.

"We conducted a broad effort to educate computer manufacturers, retailers and consumers about the hardware requirements to run different versions of Windows Vista," the company said in a statement. "This well-documented effort occurred as part of the Windows Vista Capable program. We look forward to presenting this information to the court and addressing all other issues raised in this lawsuit."

Details of the lawsuit were reported Tuesday by The Seattle Post-Intelligencer.

Colin Barker reported for ZDNet UK from London