The next major Windows 10 update, the Anniversary Update, is going to be released just slightly too late for its namesake event. The operating system first shipped on July 29, 2015. The Anniversary Update will come a few days after the first anniversary of that release, on August 2.

To celebrate the update, Microsoft is running a promotion until August 14: buy a Surface Pro 4 or Surface Book along with an Xbox One from the Microsoft Store and you'll get $300 off the price. Dell is offering a free TV to students buying any system costing more than $699, and other OEMs are likely to run promotions, too.

The current intent is for the PC release to be simultaneous with the phone release and the Xbox One release. The software isn't done yet, so it's always possible that last-minute bugs will derail this plan, but with PC, phone, and console all building from a common base, Microsoft should be able to update them all in tandem.

On the PC, the major features of the Anniversary Update are more powerful Ink features for pen-enabled systems; a more capable Cortana with integration with the Cortana apps on Windows 10 Mobile, iOS, and Android; Extensions and better standards support in the Edge browser; better enterprise security using Windows Defender Advanced Threat Protection; better gaming support in the Windows Store; and new classroom features to make it easier to have shared-use systems in education scenarios.

These bigger feature changes come with a range of smaller refinements, such as a revised Start menu layout, a system-wide dark theme, and perhaps most excitingly, a new Linux subsystem that provides native support for running Linux applications on Windows.

Over on the Xbox, the major new features are the app store and Cortana support. The new system software also brings support for background music and gives control over the system language.

With Windows now being delivered "as a Service," this update will be available for free to all Windows 10 users, including those that took advantage of the free upgrade offer for users of Windows 7 and 8.1. That offer, Microsoft insists, will end on July 29, and anyone wanting to upgrade after that date will have to buy an upgrade license. The company says that there are now more than 350 million Windows 10 users (up 50 million since early May), with 96 percent of its major enterprise customers now piloting or deploying the operating system. There's still a long way to go to reach the planned target of 1 billion Windows 10 users within the first two to three years, but it's clear that the upgrade offer has helped attract people to the platform.