Windows 10 (original release)

Windows 10 (codenamed Threshold, also referred to as Windows 9 or Windows TH) is the successor to the Microsoft Windows 8.1 operating system released on 2015-07-29. It was believed to be called Windows 9, but this was revealed to be mistaken eventually, on 2014-09-30. Rumours 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. Screenshots of Windows 10 build 9834 were released on 2014-09-11 which show a revised Start menu interface and additional improvements to the Windows operating system. Windows 10 is a revolutionary release, being the first to fully utilize the potential of Windows Update in order to provide features and fixes to the masses much faster, while also using foolhardy geeks as guinea pigs to provide rigorous testing (referred to as the 'Windows Insider Program'). Windows 10 garnered 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
''BetaWiki list only those builds with more information available (i.e. screenshots, photos, etc.) or ones released outside Microsoft (Partners, WIP). The rest can be found on BuildFeed.''

Windows Update ESD Listing

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

Pre-Technical Preview (Early Development)
A small number of builds from the pre-Technical Preview page are known. However, all but one of these supposed builds have been proven fake. The only legit pre-TP build was compiled just before the first Technical Preview, albeit in a different branch.

Technical Preview (6.4.9841-10.0.10061)
The Technical Preview was the first phase of the Windows Insider program. The first build released was 9841, and the last build released during the TP phase was build 10061.

Threshold Wave 1-class Insider Preview (10.0.10074-10.0.10166)
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.