A recent report revealed that Microsoft has broken its promise again regarding its Windows 10 Phone upgrade. The software giant told all of its Lumia mobile phone owners that it would upgrade their Windows 8 OS into Windows 10 but it didn't happen.

Earlier, in December 2015, the tech giant had promised it would release the Windows 10 Mobile OS. But that month came and went without any update coming from the company.

Then, the Redmond, Washington-based company indicated that it would release the said update last month. But again February came and went and no update was released.

We are now in the last two weeks of March and finally, there is a report that the Windows 10 OS update will finally see the light.

But there's a catch: those who own the Lumia 920 and Lumia 1020 will be stuck with their Windows Phone 8. Therefore, not all Lumia users will enjoy the upgrade as promised by the tech giant.

This update was one of the most awaited OS upgrade for Lumia owners. But the computer company was already in a panic mode and felt they need to release the update now because of the heat coming from exasperated customers.

Already, scores of Windows Phone users are shifting to other platforms. This is shown by the significant drop of its market share of approximately 50 percent in 2015. Considering that only 10 percent of the present mobile phone industry is Windows-based, that drop is considerable.

Of the 10 percent of such phones, only 1 percent has Windows OS 10. With this recent release, it is expected that this percentage will start to rise.

According to Microsoft, the official list of supported Lumia phones include

• Lumia 435
• Lumia 532
• Lumia 535
• Lumia 540
• Lumia 638 1GB
• Lumia 636 1GB
• Lumia 635 1GB
• Lumia 640
• Lumia 735
• Lumia 730
• Lumia 830
• Lumia 930
• Lumia 1520