Microsoft's goal of upgrading all Windows Phone 8 handsets to Windows 10 is looking increasingly unlikely, as many phones lack the prerequisite software updates.
Microsoft recently told Neowin it's hoping to bring Windows 10 Mobile to all devices running the latest Lumia Denim software. But at the moment, Denim is running on only 14 of the 24 Lumia handsets sold in the United States.
In other words, more than a third of modern U.S. Windows Phones aren't even eligible for the upgrade. That's quite a change from last November, when Microsoft's Lumia Twitter account promised free upgrades for all Windows Phone 8 devices.
Why this matters: If Microsoft can't figure out a way to offer updates to users who want Windows 10 Mobile, this will go down as another example of the company leaving users behind as it scrambles to find a viable smartphone strategy . Microsoft says Windows 10 Mobile will be different, as the company will deliver updates itself instead of handing duties to wireless carriers, but it's still unclear how this will work , and users could have yet another reason to be skeptical.
How we got here
Almost immediately after Microsoft's Lumia Twitter account told customers to expect an upgrade, Microsoft started walking back that claim. The compapny told VentureBeat that "we can't predict that all devices will be upgradeable, but it is our intention that the Lumia smartphone line be upgradeable to Windows 10."
In January, Microsoft moved the goalposts even further, aiming for "the majority of the Lumia phones running Windows Phone 8 and 8.1" to get Windows 10. While some Microsoft observers speculated that this statement was just posturing on Microsoft's part, and that all modern Windows Phones would get the upgrade one way or another, this appears to be wishful thinking. Microsoft has made no such promises in the intervening months, and hasn't described any way for users to get Windows 10 Mobile if their wireless carriers don't deliver the upgrade.
Meanwhile, Microsoft has just released a list of 10 phones that will be first in line to get Windows 10 Mobile, whenever it's available: Lumia 430, Lumia 435, Lumia 532, Lumia 535, Lumia 540, Lumia 640, Lumia 640 XL, Lumia 735, Lumia 830, and Lumia 930.
Even the initial upgrade list has some notable omissions, including the Lumia 1020, Lumia 1520, and Lumia Icon, but at least those flagships have Demin and could therefore get Windows 10 Mobile in the future. It seems that many other users won't be so lucky.