Microsoft has failed to trademark the name of its new cloud-based operating system, Windows Azure, internet searches revealed on Monday, even though it registered the Windows Azure website 14 years ago.

According to searches conducted by PC Advisor's sister title Computerworld US, Microsoft has not applied for a trademark for either 'Windows Azure' or 'Azure Services Platform' with the US Patent and Trademark Office. Microsoft used both names to describe the software-plus-services technology it announced yesterday.

Microsoft's own trademark list also omits Azure, though that list has not been updated since earlier this month.

Other Microsoft technologies, including Windows Vista, DirectX, Hyper-V and Surface, however, have been trademarked by the company.

On Monday, Ray Ozzie, the company's chief software architect, unveiled Windows Azure as Microsoft's cloud-computing platform. Ozzie said that work had started on Azure just before Amazon launched its own Elastic Compute Cloud (EC2). The two platforms, EC2 and Azure, will likely compete for developer attention.

Microsoft will release a preview of Azure at the Professional Developers Conference (PDC), where Ozzie debuted the technology. He did not spell out when Azure would be generally available, however.

But while Windows Azure doesn't show up in the US Patent and Trademark Office's database, Microsoft more than planned ahead when it registered the '' website.

A search of registered sites found that Microsoft grabbed - the site it also unveiled Monday that hosts information about the new platform - in October 1994. The site is currently registered at, a cut-rate domain registrar that currently is running a $9.99 per year special.

Microsoft also owns the '' domain, which it registered in November 2003.