Windows 10 build 10240 (th1)

Build of Windows 10
OS family
Architecturex86, x64
Works in
TCB.png TCBGallery.png

Windows 10 build 10240 (th1) is the official RTM build of the original release of Windows 10. This build was released on 15 July 2015 to Windows Insiders and became the final build of the TH1 cycle on 29 July 2015. It is the first build to become available for consumers to install and was also available as a free upgrade for Windows 7 and 8.1 users until 29 July 2016.

It contains very few changes over build 10176, a leaked RTM candidate, however, it does include several changes over 10166, the last preview build 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 the previous builds.

Build number[edit | edit source]

Build 10240.16384 is the last RTM build with the build number divisible by 16 and the delta number bumped to 16384. This is a remnant of the older 20-bit revision numbering scheme, which used the most significant bits in the delta number to encode extra information. The 4 least significant bits of the build number were reserved for the Service Pack number, although Microsoft hasn't produced a Service Pack since the release of Windows 8.

The limited range of usable revision numbers for a single Service Pack under this numbering scheme lead to the build number of Windows Server 2008 Service Pack 2 being bumped to 6003 towards the end of its lifetime in order to make sure that future updates continue to have distinct version numbers.

Editions and keys[edit | edit source]

Edition / SKU Key
CoreCountrySpecific N2434-X9D7W-8PF6X-8DV9T-8TYMD
Education (edition upgrade only) YNMGQ-8RYV3-4PGQ3-C8XTP-7CFBY
EducationN (edition upgrade only) 84NGF-MHBT6-FXBX8-QWJK7-DRR8H
EnterpriseEval VPMWD-PVNRR-79WJ9-VVJQC-3YH2G
EnterpriseN WGGHN-J84D6-QYCPR-T7PJ7-X766F
EnterpriseS NK96Y-D9CD8-W44CQ-R8YTK-DYJWX
EnterpriseSNEval 7M88N-MTVMR-VC46G-4K4R6-KTQF7
Professional VK7JG-NPHTM-C97JM-9MPGT-3V66T
ProfessionalN 2B87N-8KFHP-DKV6R-Y2C8J-PKCKT

Findings[edit | edit source]

Dark mode[edit | edit source]

The dark theme can be enabled by editing the registry. However, this method will only work if you’re using Windows 10 Pro, Education, and Enterprise editions. It won’t work on Windows 10 Home. Navigate to:


(manually create the "Personalize" key if there's not one), then create a DWORD key named AppsUseLightTheme. After that, you need to repeat the above-mentioned steps, but for:


Colored title bars[edit | edit source]

Microsoft did not introduce the option to change the color of title bars until Windows 10 build 10525, however, you can enable colored title bars in version 1507 using a theme hack. Notice that inactive and active title bars have the same color, the only difference is that the inactive title bar text and buttons are grayed out.

Leftovers[edit | edit source]

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[edit | edit source]

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[edit | edit source]

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[edit | edit source]

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 navigating to:


and changing UseActionCenterExperience value to 0, and then signing out of Windows and signing back in.

Notification Area Icons Control Panel[edit | edit source]

The Notification Area Icons applet in Control Panel that was present in earlier versions of Windows has been moved to the Settings app by this point, and it's no longer present in the RTM. Versions 1507 until present still include the working applet, but it is hidden. To open it, use the following command: explorer.exe shell:::{05d7b0f4-2121-4eff-bf6b-ed3f69b894d9}

Bugs[edit | edit source]

  • When choosing "Restore default icon behaviors" in the Notification Area Icons Control Panel, the window hangs and then crashes. This bug does not always happen.

Gallery[edit | edit source]