A vision of “one Microsoft” offering a unified experience across Windows PCs, Windows Phone and the Xbox One is emerging, as the company will reportedly unveil the plan for Windows 9 this April at its annual Build Developer Conference.

Technology blogger Paul Thurrott reports that Windows 9 could be released to the general public as soon as April 2015. Microsoft is apparently looking at Windows 8 as a misstep in the vein of Windows Vista, and will use Windows 9 to start fresh as it did with Windows 7.

Thurrott calls Window 9 a “make or break release” for Microsoft, noting that “Windows 8 has set back Microsoft, and Windows, by years, and possibly for good.” Critics lamented Windows 8 for slow functionality and a poorly conceived user interface, and devices running the operating system have sold poorly alongside those running operating systems such as Apple’s iOS and OS X and Google’s Android.

The top Windows 9 featured outlined in the report include the ability to run Metro apps in windowed versions on the desktop, as well as an update to the UI called Metro 2.0. Since the Start button made its way back with Windows 8.1 following its removal upon the OS’s initial release, Thurrott says that a traditional Start menu could become an option for users in Windows 9 as well.

Microsoft will announce Windows 9 at Build 2014, but not release any of the new OS’s code since development will not begin until later in the month. Earlier reports had suggested that the updates to Windows might be marketed as Windows 8.2.

“Threshold” was the name of the planet that the halo ring orbited in the first Halo game released for the original Xbox in 2001. Microsoft appears to be employing a naming scheme across its services based on the “Halo” franchise, with “Threshold” joining “Cortana,” the super-smart Siri-equivalent that was glimpsed in beta versions of Windows Phone 8.1, or “Blue.”

Microsoft is also working toward offering a single app store across all platforms, and to make the developer tools for each of the three platforms more similar according to ZDNet's Mary Jo Foley. Windows Phone 8.1 (code-named “Blue”) will launch around the same time that PCs are updated to Windows 8.1 Update 1, set for release in the spring and early summer of 2014.

Follow Thomas Halleck on Twitter @tommylikey