Windows 10 version history

Windows 10 is a major release of the Windows NT operating system developed by Microsoft. Microsoft described Windows 10 as an "operating system as a service" that would receive ongoing updates to its features and functionality, augmented with the ability for enterprise environments to receive non-critical updates at a slower pace or use long-term support milestones that will only receive critical updates, such as security patches, over their five-year lifespan of mainstream support. It was released in July 2015. Windows Insider#Channels Windows 10 Insider Preview builds are delivered to Insiders in three different channels (previously "rings"). Insiders in the Dev Channel (previously Fast ring) receive updates prior to those in the Beta Channel (previously Slow ring), but might experience more bugs and other issues. Insiders in the Release Preview Channel (previously Release Preview ring) do not receive updates until the version is almost available to the public, but are comparatively more stable. Mainstream builds of Windows 10 are labeled "YYMM", with YY representing the two-digit year and MM representing the month of planned release (for example, version 1507 refers to builds which initially released in July 2015). Starting with version 20H2, Windows 10 release nomenclature changed from the year and month pattern to a year and half-year pattern (YYH1, YYH2). Windows 10 (original release) Windows 10, version 1511 The second stable build of Windows 10 is version 1511 (build number 10586), known as the November Update. It was codenamed "Threshold 2" (TH2) during development. This version was distributed via Windows Update on November 12, 2015. It contains various improvements to the operating system, its user interface, bundled services, as well as the introduction of Skype-based universal messaging apps, and the Windows Store for Business and Windows Update for Business features. On November 21, 2015, the November Update was temporarily pulled from public distribution.