Windows 10 users will get new features and functions for a full 10 years from the time the OS is purchased, a major shift in how Microsoft offers OS support.\n"Microsoft's intention is that you will get 10 years minimum of updates for Windows 10, both feature and security updates, from when you get it," said Gartner analyst Steve Kleynhans, who tracks the Redmond, Wash. developer and was briefed by the company on its plans. "They intend to provide the full 10 years of support, which means giving feature and security updates for that computer for 10 years, provided the OEM continues to support the device."\nKleynhans has been pushing Microsoft for clarity on its statements about Windows 10 support and paraphrased from an email Microsoft sent him Tuesday about its support plans. He would not share the exact contents of the email.\nThe details from Microsoft mean that the usual retirement dates for support announced in the past for previous versions of Windows will no longer be used.\nIn brief, here's how the new support structure will work:\n\nThe 10-year support clock starts running when a customer starts using Windows 10. "If I bought a new PC four years from now, I will get 10 years from that point," said Kleynhans.\nThere's a caveat: The hardware has to be able to support the changes and updates. "If something happens, say you have a device with a 16GB SSD and suddenly at some point they can't fit Windows 10 on a 16GB SSD, sorry, you're out of luck. They'll support [Windows 10] until the hardware physically can't handle it."\nIt remains unclear how Microsoft will keep track of that Windows 10's support decade. One option would be to start the clock running on the product activation date of the OS. Another would be to track when the user first logs onto the machine with Microsoft Account credentials.\nCustomers -- mainly enterprises -- that use the Long-term Servicing Branch (LTSB) for updates will continue to get the levels of support Microsoft has offered in the past: five years of Mainstream support and five more years of Extended support. "That is very specific to the LTSB," said Kleynhans. LTSB is one of four update tracks or "branches" that determine when a customer receives updates; it will be available only to organizations with volume licensing deals for Windows 10 Enterprise; and it requires the Software Assurance program as well. (LTSB provides only security patches and critical bug fixes, not new features or other changes.)\n\n"When they talk about changing the servicing model for the OS, moving it forward, keeping it updated, they are rethinking the whole process," Kleynhans said. "It's significantly different than what we've had in the past."\nWith reports by Gregg Keizer at Computerworld.