With the release of Windows 10, Microsoft(NASDAQ:MSFT) will deliver a single operating system which powers computers, tablets, and phones.

The move could boost the struggling Windows phone business which commands less than 3% market share as of the third quarter of 2014, according to IDC. By offering a unified experience across all devices, Microsoft hopes to make its phones an attractive option for people using Windows elsewhere.

PeriodAndroidiOSWindows PhoneBlackBerry OSOthers
Q3 2014 84.4% 11.7% 2.9% 0.5% 0.6%
Q3 2013 81.2% 12.8% 3.6% 1.7% 0.6%
Q3 2012 74.9% 14.4% 2% 4.1% 4.5%
Q3 2011 57.4% 13.8% 1.2% 9.6% 18%

Source: IDC

The current generation of Windows Phone runs on a separate operating system. The OS looks a lot like Windows 8 -- at least the app-driven part of it which was once known as the "Metro" screen -- but it is a different iteration of Windows that requires its own apps. Windows 10 will change that, giving Microsoft one OS for all its devices.

One app store
One of the biggest complaints regarding Windows Phone has been its shortage of apps compared to Apple or Google. Microsoft claims more than 300,000 apps are available, but that number falls short of the more than 1 million available for iOS and Android phones, according to CNET. 

Developers are understandably hesitant to build apps for an operating system that has only 3% market share. This should change with the release of Windows 10 where apps will work across phones, tablets, and PCs. That balloons the installed user base and makes developing for Windows Phone a much more attractive option.

What was once a tiny audience will now include customers who take the free upgrade to Windows 10 on their tablets, desktops, and laptops.

Universal, yet unique
While Windows 10 will be the same operating system across all devices, the OS will be optimized to deliver the best possible experience on each platform. On phones, that means a user interface designed to work best on a mobile device. The company detailed some of those features in a blog post touting the release of the first preview version:

  • Full-size Background Image for Start: We believe phones should be intensely personal -- so we've added another option to customize the start screen with a full-size background image.
  • More Quick Actions in Action Center: We've increased the number of quick actions available to you. Windows Phone 8.1 has four programmable quick actions -- but with Windows 10 you also get an expanded view that can now have up to three rows.
  • Interactive Notifications: Notifications are now interactive, allowing you to take action directly like dismissing an alarm, or seeing images for maps. For example, for text messages, when the toast pops, you can quickly reply inline via text or voice.
  • Significantly enhanced speech-to-text capability: You can talk to virtually any data field you choose. Your words show up as you speak them -- and punctuation appears automatically. This feature is smart enough to understand when to use "two" -- the number -- instead of "too" as in "also."
  • More powerful Photos app: From your very first launch, Photos will show the aggregated set of all your local photos and all your OneDrive photos

It is one Windows, but the experience will be different or familiar depending on the device in your hand.

Microsoft's Joe Belfiore explains how the Windows Phone Insider's preview works. Source: Microsoft

Cortana is key
Microsoft is making a huge bet on its voice assistant and has decided to embed Cortana in all platforms.

"Cortana will be more powerful and capable in Windows 10 than ever before, with more capabilities and language support than ever before," according to the blog post.

Voice control will be a growing part of how users interact with the operating system, and if it works well, it should remove some of the learning barriers for the new OS. Cortana, which I have tested, is generally more useful than Siri and could be a key driver for Windows 10.

A big gamble
Microsoft is betting big on the idea that one OS for all its devices makes Windows Phone more attractive. It should be enticing to corporate users who run Windows-based machines at work and iPhones or Android devices when mobile.

But most companies already support one OS for PCs and another for tablets and yet another for phones. Microsoft is correct that one platform simplifies things, but that would have been a stronger argument a few years ago.

Now, there is no doubt Microsoft is offering a strong option which will have developer support but whether iOS and Android users will switch remains a major question.

Daniel Kline owns shares of Apple and Microsoft. He will switch to Windows Phone when it offers the Starbucks app. The Motley Fool recommends Apple, Google (A shares), Google (C shares), and Starbucks. The Motley Fool owns shares of Apple, Google (A shares), Google (C shares), and Starbucks. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.