Windows 10 Threshold 1

The original version of Windows 10 is the first version of Windows to utilize the Windows Insider Program for its development. Public previewing started in October 2014. While this version is only stable for PC and IoT, there are also preview builds for Mobile and Server from the Threshold 1 branches, but neither have a stable release.

Mobile

10 releases

No stable release
Slow

10166.0

22 July 2015

Server

11 releases

Windows 8.1
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