Microsoft Lumia 640 XL
Microsoft Lumia 640 XLIBTimes India/Raymond Ronamai

Microsoft has been running behind schedule in releasing Windows 10 Mobile update to its eligible devices and this could have left many Lumia device owners frustrated. The software was supposed to be available in December, but it is yet to see the light of the day.

Windows 10 Mobile update schedule could go haywire, and that's what Gabe Aul, corporate vice president, Engineering Systems Team, Microsoft, has hinted at in a note on the company's blog. He said that Windows 10 Mobile devices will get builds first and not Windows Phone 8.1.

"I know that a lot of Windows Insiders are eager to know what's going on with Mobile builds. As you know we've already released the Lumia 950, 950XL, and 550 devices with Windows 10 Mobile preinstalled, and we're still on track to release Windows 10 Mobile as an upgrade to existing devices early this year as we planned. The team is working now by looking at data and reports from Insiders who have upgraded their devices to preview builds, and ensuring that we deliver a great upgrade experience to customers. We're excited about making the upgrade available, and will share new information with you just as soon as we can on how the rollout will happen," wrote Gabe Aul. 

He went on to say that the company is getting ready to start sharing new preview builds to devices that shipped with Windows 10 Mobile – the 950, 950XL, and 550 – and expand to other devices after Windows 10 Mobile is rolled out.

It is now clear that only owners of Lumia 950, Lumia 950 XL and Lumia 550 will see the latest builds initially, which means users of other eligible devices like Lumia 430, Lumia 532, Lumia 535, Lumia 540, Lumia 640, Lumia 640 XL, Lumia 735, Lumia 830, Lumia 930 and all Windows 8.0-based phones will get Windows 10 Mobile update late. You will need to buy a new phone if you badly want Windows 10 Mobile builds.

However, Bouygues Telecom, French mobile phone and internet service provider, has hinted in a response to a query posted by a Twitter user, with username Joel Devaux, that the software update will not come until the end of February. In the meantime, Vodafone Australia has claimed that Lumia 640, Lumia 640 XL, Lumia 535 and Lumia 930 have completed software testing and are awaiting confirmation for a rollout.