A forthcoming addition to Microsoft's Windows operating system will give users the ability to burn optical discs encoded in the Blu-ray high-definition movie format directly from their desktops and without having to use third-party software, according to Microsoft.

The Windows Feature Pack for Storage, currently in beta testing, includes an application programming interface for Blu-ray media. It "enables the Windows platform to do master-style optical burning on Blu-ray media," Microsoft said in a statement posted Monday on a Web site it maintains for developers.

Microsoft's decision to add direct Blu-ray support to Windows may signal a broader move by the company to embrace the format, developed by Sony, at least partly. In the HD wars, Microsoft initially placed itself in the HD DVD camp by introducing an external disc player for its Xbox 360 console capable of playing the Toshiba format.

But Toshiba's decision in February to effectively kill off HD DVD may have left Microsoft with little choice but to warm up to Blu-ray. And though Microsoft competes fiercely with Sony in the console market, it also partners closely with the Japanese electronics maker in the Windows PC market -- a fact that may have contributed to Redmond's decision to support Blu-ray on Windows.

Microsoft is making the Windows Feature Pack for Storage available for both Windows XP and Windows Vista.

Microsoft, however, is still hedging its HD bets. Through its Xbox Live gaming service, the company offers numerous HD movies and television programs that can be downloaded directly to the Xbox 360. Microsoft also recently inked a deal with Netflix to stream movies directly from the online rental service to the Xbox. It's not clear, however, how much of that content will be in HD.

Beyond Blu-ray support, the Windows Feature Pack for Storage adds a security feature that allows users to restrict access to portable devices (such as a USB Flash drive) via certificates or passwords. It also provides driver support for new smart card form factors, including ICCD/CCID.

Microsoft did not provide a final release date for Windows Feature Pack for Storage.