Microsoft is yet to announce the Windows 10 Mobile update schedule for its devices, but users of old handsets could be in for a big disappointment if one is to go by latest report. It appears old Microsoft devices may get the firmware only by February-end, or even later.

Replying to a query on possible release of Windows 10 Mobile to Microsoft's old Lumia devices from a Twitter user by the name Joel Devaux, French mobile phone and internet service provider, Bouygues Telecom said the software update would not come until the end of February. 

Bouygues Telecom's tweet may disappoint many Lumia users, as several reports had given the impression that the software update would come to all Lumia devices sooner than later.

Giving a clear hint that the Windows 10 Mobile update is not far off, Vodafone Australia has revealed software testing for Microsoft Lumia 640, Lumia 640 XL, Lumia 735 and Lumia 930 has been completed and the update is awaiting confirmation for roll out schedule. 

There were also reports doing the rounds that the Lumia 535 and Lumia 640 have received Windows 10 Mobile, but it could be just another rumour.

Microsoft hasn't announced the release schedule of Windows 10 Mobile to Lumia devices, but its rollout is imminent and may happen sooner than expected. The software will be rolled out initially to the Lumia 430, Lumia 532, Lumia 535, Lumia 540, Lumia 640, Lumia 640 XL, Lumia 735, Lumia 830 and Lumia 930 before Windows 8.0-based phones get it.