Windows 10 (original release)


 *  This article is about the original release of Windows 10 from July 2015. See Microsoft Windows for the subsequent feature updates released for Windows 10.

Windows 10 (codenamed Threshold, also referred to as Windows 9 or Windows TH) is the successor to Windows 8.1 released on 29 July 2015. It was believed to be called Windows 9, but this was revealed to be mistaken eventually, on 30 September 2014. Rumors have spread that "Windows 9" was skipped because the name triggered code for Windows 9x in some applications, most of the time leading to an error message on the application not supporting Windows 9x. Windows 10 intends to address some of the complaints that were made in response to the user interface in Windows 8. Windows 10 is a revolutionary release, being the first to fully use Windows Update to provide features and fixes to the masses much faster, while also providing a group that people who want to test its future releases can join (referred to as the "Windows Insider Program"). Windows 10 gained largely positive reviews and has easily exceeded the market share that Windows 8 gained in the same period.

Due to the switch to a periodical release system, many builds after the RTM are still labeled "Windows 10" but are listed on separate pages. Builds for the multiple updates can be seen on their respective pages.

And there's multiple updates available since 2015.

Builds
BetaWiki lists only those builds with more information available (i.e. screenshots, photos, etc.) or ones released outside Microsoft (Partners, WIP).

Windows Update ESD listing

 *  See here for a list of Windows 10 ESD files that have been gathered from the Windows Update infrastructure.

Technical Preview
The Technical Preview was the first phase of the Windows Insider program. The first official build released was 9841, and the last official build released during the TP phase was build 10061.

Insider Preview
This phase of development began with build 10074, which was a quality build, at least going by the standards set by 10041/10049. The final phase of TH1 Insider Preview development ended with build 10166, which was extremely close to the RTM build, build 10240.