Microsoft is starting at last its rollout of Windows 10 to a subset of its Windows Phone 8.1 devices, officials said on March 17.
The availability of Windows 10 Mobile as an upgrade "will vary by device manufacturer, device model, country or region, mobile operator or service provider, hardware limitations and other factors," according to Microsoft's "How to Get Windows 10 Mobile" page.
If and when the update -- Build 10586.164 -- is available, users will need to plug their phones in and connect to Wi-Fi to get the update. They also will have to free up enough storage space to download and install the update. The Microsoft Upgrade Advisor app will help users figure out how to free up space to install the upgrade.
Users also can run the Upgrade Advisor app to determine whether their particular Windows Phone is eligible to get the update to Windows 10 Mobile.
Update: These are the phones eligible for the Windows 10 Mobile update:
- Lumia 1520
- Lumia 930
- Lumia 640, 640 XL
- Lumia 730
- Lumia 735
- Lumia 830
- Lumia 532
- Lumia 535
- Lumia 540
- Lumia 635 1GB,
- Lumia 636 1GB,
- Lumia 638 1GB,
- Lumia 430
- Lumia 435
- BLU Win HD w510u
- BLU Win HD LTE x150q
- MCJ Madosma Q501
Because some of the Windows 10 Mobile features are hardware dependent, certain Windows 10 Mobile features like Continuum and Windows Hello won't work on existing phones that are updated to Windows 10 Mobile.
There are also a number of current Windows Phone 8.1 features that users will lose or see modified if they update to Windows 10 Mobile.
Among those features that may be modified or removed: Me Tile and Me Card; notifications for missed calls, messages and emails on contact tiles; Cortana's ability to search for apps, settings, email, text messages, contacts and QR Codes on the device; ability to open apps through voice commands; and MDM functionality to prevent saving and sharing Office documents. The full list of deprecated features is here, under the Mobile tab.
Microsoft released to manufacturing Windows 10 Mobile back in November and made it available since then on several new Windows Phone handsets, starting with the Lumia 950 and 950 XL. Since that time, the company has been updating and fixing Windows 10 Mobile.
Microsoft also posted today a list of Windows Phones that, after updating to Windows 10 Mobile, will be eligible to be part of the Windows 10 Mobile Insider preview, moving forward.
Update No. 2 (March 20): I've had a number of individuals ask how Microsoft decided on which phones will and won't be offered the Windows 10 Mobile update. Microsoft Windows Insider chief Gabe Aul said Microsoft evaluated Insider tester feedback over the pas 12 or so weeks as to which phones performed well when running Windows 10 Mobile test builds to make the call.
Aul also said the list Microsoft provided is pretty much final. There won't be a second round of phones added to the supported list. However, he did note that Microsoft still is considering whether or not to add the Lumia Icon to the list of phones that will get Windows 10 Mobile.