Microsoft has pushed back once again the launch date of the mobile operating system version of Windows 10. Windows users will have to wait until next year to see the roll-out of Windows 10 mobile.

A Microsoft spokesperson told ZDNet that the roll-out of the mobile OS update will be arriving to select Windows 8 and Windows 8.1 phones. The representative said last Dec. 17, "This November we introduced Windows 10 to phones including brand new features such as Continuum and Universal Windows Apps with the introduction of the Lumia 950 and 950 XL. The Windows 10 Mobile upgrade will begin rolling out early next year to select existing Windows 8 and 8.1 phones."

Back in August, Microsoft revealed to insiders that Windows 10 mobile would be made available for the Lumia 430, Lumia 435, Lumia 532, Lumia 535, Lumia 540, Lumia 640, Lumia 640 XL, Lumia 735, Lumia 830, and Lumia 930.

Currently, the mobile OS is available for the Lumia 950 and 950 XL which launched out of the box with Windows 10.

The Windows 10 mobile OS has seen many iterations as the in-house built system has various errors in released builds so far. Tech Radar said that it was earlier thought that the build would be available in September, but the roll-out of the OTA update for non-Lumia 950 phones has not yet happened until today.

The Lumia 950 and 950 XL currently have builds for the Windows 10 mobile OS, but it is not without problems either. The Microsoft Lumia 950 sports a Qualcomm Snapdragon 808 processor to run the operating system, and also has a 5.2-inch quad AMOLED display. The Lumia 950 XL sports a bigger 5.5-inch display and is powered by a Snapdragon 810 processor.

The Lumia 950 and 950 XL both currently run on the RTM version of Windows 10 Mobile which was launched in November, almost the same time the Windows-built handsets were shipped out to the early adopters of the handsets. There is no specific date given by the Redmond-based company as to when the roll-out of the Windows 10 mobile OS will occur, and insiders will have to make further ado with 'early next year' for the meantime.