Windows 10 has been well received, with Microsoft putting right much of what it got wrong in Windows 8.
But let us be clear, it is still Windows, weighed down with features and functions that many users - both business and consumer - can do without.
Microsoft must be concerned, as it can see that Google’s Chrome OS is gaining market interest, and it knows that Apple is introducing Windows-like productivity features with iOS 9.
With Windows RT all but abandoned, Microsoft needs a new approach to protect its flank.
In truth, Microsoft still needs a replacement for the ill-fated Windows RT.
You can almost hear the sound of relief as Microsoft executives read the positive reviews extolling the virtues of Windows 10.
Let there be no doubt, Windows 10 is a robust and reliable workstation-grade operating system, but this only gets the desktop market back on track after the derailment caused by Windows 8 three years ago.
Windows 10 Mobile - the successor to Windows Phone 8 - is still in beta, but Ovum expects it will be released before the end of the year.
Designed for smartphones and small tablets with a screen size of less than eight inches, Windows 10 Mobile may benefit from Microsoft’s investments in the desktop OS and its new Windows Universal Office apps.
But the company is scaling back its expectations in the smartphone market, having written-off the Nokia acquisition and all but conceded the smartphone market to Google and Apple.
With desktop, smartphone, and small tablet accounted for, Microsoft still has to address the threat posed by iPads (especially when coupled with a Bluetooth keyboard cover) and Chromebooks in the entry-level laptop/large tablet market.
Windows RT was Microsoft’s answer to this threat back in 2012, but the company has abandoned the project in its current form, with only minor updates expected for the remainder of the operating system’s support lifecycle.
As any IT support professional will tell you, the Windows operating system is a high-maintenance product, even with a sophisticated set of management tools.
A typical installation of Windows 10 consists of more than two hundred services that need managing, maintaining, and protecting, and there are more than one hundred features that can be turned on or off.
It is not a lightweight, cloud-first, mobile-first operating system. Microsoft must therefore find an alternative for those users who do not need a workstation-grade operating system, or hand this important market over to Google and Apple.
By Richard Edwards - Research Analyst, Ovum