Microsoft is reporting strong user uptake for its Windows 8 operating system update.

The company said that in its first days on the market, the newest version of Windows has been installed by some four million users.

Speaking at the company's Build developer conference, chief executive Steve Ballmer was quoted as saying that the company has seen strong interest from early adopters who have been offered the 25 download price.

The news comes despite early doubt cast on the platform by a consumer survey. The study suggested that as many as half of all end users have not yet heard of Microsoft's latest offering.

The release of Windows 8 is part of a three-pronged approach by Microsoft to overhaul and update its mobile and desktop patterns.

In announcing its Windows Phone 8 platform earlier this week, the company described a connected environment in which users can access and transfer content across the Xbox, Windows and Windows 8 environments, as well as cloud storage and collaboration platforms.

Ballmer said that the company would use the interoperability and connectivity advantages offered by the strategy to differentiate its mobile and desktop platforms from competitors.