Microsoft have made available a new preview build of their upcoming operating system in the form of Windows 10 build 10120, but like some previous version this one is exclusive to a select group.
That is to say, this new version is showing up for company employees.
Russian leaker WZor revealed this news today, confirming that build 10120 is available internally at Microsoft. This usually is the first step before the rollout of a new version for Windows Insiders, meaning we can expect an update soon.
Here’s a screenshot:

The next few builds are not expected to bring any major improvements over the existing version, other than refinements and bug fixes, of course. Spartan could be renamed to Microsoft Edge, though.
But Microsoft certainly seems to be moving the OS closer to its final form with these new releases, each of which is more polished than the previous ones.
We can probably expect build 10120 (or something similar) to ship by the end of the month. This week Redmond is on track to release a new build of Windows 10 Mobile, and the PC version is unlikely to arrive at the same time.
source:windows10update