Microsoft has confirmed that Windows 10 will be released globally—for PCs and tablets only—on July 29 as a free upgrade for anyone running Windows 7 or Windows 8.1.

You have one year from July 29 to get your free upgrade to Windows 10, after which Microsoft will "continue to keep it current for the supported lifetime of the device—at no cost." There's no word on what the "supported lifetime" actually is, but it's probably some loose wording to prevent Microsoft from falling into the same trap as Windows XP. The company likely doesn't want to support Windows 10 on devices that are 10, 15 years old.

The annunciatory blog post, penned by operating system chief Terry Myerson, is light on any further details. There's no guidance on the release date for Windows 10 Mobile, and it isn't clear how many of the seven Windows 10 SKUs will be released on July 29.

The overall timing is very aggressive, especially when you consider that the RTM (the final version to be sent to OEMs) would need to be distributed in the next few weeks. As we reported last week, it should still be a stable, production-ready build of Windows 10—but it could lack some features that will be patched in later via Microsoft's new rolling "Windows as a service" updates.