Windows 10 build 10240 (th1)

Windows 10 build 10240 is the official RTM build of the original release of Windows 10. This build was released on 2015-07-15 to Windows Insiders and became the final build of the TH1 cycle on 2015-07-29. It is the first build to become available for consumers to install and was also available as a free upgrade for Windows 7 and Windows 8.1 users until 2016-07-29.

It contains very few changes over build 10176, a leaked RTM candidate, however, it does include several changes over 10166, the last preview builds in the Threshold Wave 1 release cycle. These changes are:


 * Watermark has been removed.
 * Widespread stability improvements
 * Branch change from fbl_impressive to th1

Aside from these changes, 10240 is a build which contains only limited changes over previous builds.

Bugs and leftovers
Due to older code from beta builds or earlier versions of Windows not being removed, several older features can be re-enabled through registry tweaks or system file patches.

8.1 Start screen
One of the most known leftovers in 10240 is the Windows 8.1 start screen hack. In July 2015, MetroFetro released patched versions of shell32.dll and twinui.dll for x86 versions of Windows 10, the use of which (and a registry file) would restore the old Windows 8.1 Start screen. x64 versions were released in May 2019, however they unlock a more buggy Start screen than their x86 counterparts. It is unknown if MetroFetro plans to release a fix for this bug.

98xx notification flyout
The use of a registry file removes the Action Center and brings back the Notifications flyout from early betas of Windows 10. Once again, it is partially broken as it wasn't intended to be used in RTM, as some of the icons are missing, and the text can turn pseudo-like in non-English versions of the operating system.

Other older flyouts
Several other older flyouts from Windows 8.x still exist in 10, most of which can be found here (only 1-9 work in RTM, far less of which work in later versions of 10). Though it is commonly believed tweaks 1-8 in the listed article will work, tweak 9 will also work. Tweak 9 changes the action center back to the pre-release one. You can restore it by going here HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\ImmersiveShell in the regedit and changing UseActionCenterExperience value to 0, and then signing out of Windows and signing back in.