Windows 10 Mobile Finally Released for (Some) Existing Users

After several delays, Microsoft on Thursday finally rolled out Windows 10 Mobile as a free upgrade to existing Windows Phone 8.1 users.

In its announcement of the rollout, Microsoft indicated that the upgrade will be initially available to only a "limited set of Windows Phone 8.1 devices." Microsoft's Windows 10 Mobile specifications page lists the following eligible devices: Lumia 1520, 930, 640, 640XL, 730, 735, 830, 532, 535, 540, 635 1GB, 636 1GB, 638 1GB, 430, 435, BLU Win HD w510u, BLU Win HD LTE x150q, MCJ Madosma Q501.

Although the rollout technically kicks off on Thursday, actual availability for individual users will depend on their mobile carriers, whose own processes for testing OS upgrades can sometimes result in months-long delays.

Microsoft has released an UpdateAdvisor mobile app (available here on the Microsoft Store) that Windows Phone 8.1 users can run to check their devices' eligibility. The app will also recommend ways users can free up space on their devices for the upgrade, which is about 1.4GB in size, although Microsoft warns that it can be larger in some instances.

The Windows 10 Mobile spec page has more information on upgrade requirements, as well as a few caveats related to new features such as Cortana, Continuum and Windows Hello. For instance, Cortana is limited to certain regions, while Continuum and Windows Hello are limited to certain "premium" devices.

Notably, some Windows Phone users who are currently enrolled in the Windows Insider testing program may not be eligible for the final upgrade. As Microsoft explained in its announcement:

"As Windows 10 delivers significant new innovations, many older devices are not able to successfully upgrade without an impact on the customer experience. Our goal is to only offer the Windows 10 upgrade to devices that we are confident can continue to deliver a good customer experience."

In a FAQ about the rollout, Microsoft said that users who are enrolled in the Windows Insider program but are ineligible for the final upgrade "may keep using [their] device in an unsupported state." However, Microsoft warned, "At some point in the future these devices will also stop receiving updates to the Windows 10 Mobile Insider Preview build."

Those excluded from the Windows 10 Mobile upgrade must roll back their devices to Windows Phone 8.1 using the Windows Device Recovery Tool if they want to continue running a supported OS, the FAQ said.

Microsoft has been running Windows 10 Mobile through its paces via the Windows Insider program for over a year now, and has considered the OS "feature-complete" since last summer. However, while brand-new Lumia devices have been running Windows 10 Mobile since last fall, existing Windows Phone 8.1 users have had to wait a bit longer.

Windows 10 Mobile was initially expected to be released alongside the Windows 10 desktop OS, which became generally available on July 29. However, that release date was later pushed ahead to the end of 2015, to early 2016, to late February and, finally, to mid-March.

About the Author

Gladys Rama (@GladysRama3) is the editor of, and, and the editorial director of Converge360.


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