Microsoft is taking security risks with its forthcoming Vista operating system, says software firm McAfee.
The security specialist has taken out a full-page advert in the Financial Times to alert readers to its concerns.
It feels the tech giant is increasing risks of hacks and viruses by locking out third-party software firms from its in-built security system for Vista.
The row also involves the European Union, which is watching Vista"s release for signs of monopoly abuse.
"With its upcoming Vista operating system, Microsoft is embracing the flawed logic that computers will be more secure if it stops co-operating with the independent security firms," wrote George Samenuk, McAfee"s chairman and chief executive in the advert.