Redmond: Despite its takeover of Nokia and rebranding of the Lumia range of Windows-based smartphones as 'Microsoft Lumia', the US tech giant has so far failed to ignite the market for its mobile offering.
In fact, the Windows Phone future appears to be more uncertain now than it was when Lumia was a Nokia product.
Microsoft has now launched the latest version of Windows and renamed the smartphone OS as Windows 10 Mobile.
However, the launch of its flagships - Lumia 950 and 950XL - too appears to have failed to strike a chord with smartphone users and the dwindling Windows Phone sales are expected to witness a further slide.
Even International Data Corporation (IDC) has predicted that Windows Phone would do well to hold on to its negligible, less than 3 percent marketshare. Compare that with iOS (15.8 percent) and Android (81.2 percent).
But, Microsoft is still not giving up and is, most likely, coming up with its last weapon in its armoury.
It appears to be a matter of time before the Redmond giant unveils its premium offering - Surface Phone.
The phone - when and if unveiled - could either prove to be a game changer or last nail in the Windows Phone coffin.
Microsoft is aggressive about making Windows 10 a success and the success of the Windows 10 Mobile is a key factor. That is why the company has also come up with the Continuum feature which lets one turn his Windows 10 Mobile into a PC CPU.
Microsoft's Surface series of tablets have been a success and extending that line to smartphones could prove to be a turning point for Windows Phone.
While nothing is official about the Surface Phone as yet, enough hints have been dropped that it is indeed coming.
Microsoft's chief marketing officer Chris Capossela has confirmed that the company is working on a “breakthrough” product which would be a “spiritual equivalent” of the Surface line of tablets.
It's anybody's guess that the product would be a phone.
However, it remains to be seen how a Surface Phone would be different from a Microsoft Lumia 950 or 950 XL - both of which have been designed and made by Microsoft.
And if the Surface Phone succeeds, it would be a welcome news for gadget lovers as having three leading smartphones OSs would always be better than having just two.