Windows 10 RTM Build Changelog and History

When Microsoft released the first preview build of Windows 10, its build number was 9841. It was released on September 30, 2014 via fbl_release channel of Microsoft. Since then Microsoft has released several Preview builds of Windows 10 to public.

Download Windows 10 Free Insider (Technical) Preview

Today in this exclusive article, we are going to list the major changes and new features introduced in all public Preview builds of Windows 10 released before final RTM build. We'll not mention each and every small change. We'll only highlight the important changes and features of each build of Windows 10.

Initially this changelog was a part of our exclusive Windows 10 review article but on readers demand, we are putting it in a separate article. We have added information about many new Preview builds of Windows 10 which was not given in Windows 10 review article.

So without wasting time, lets start the article!

Following are some important and worth to mention changes present in various testing builds of Windows 10:

Windows 10 Build 6.4.9841 Changelog:

It was the first Preview build of Windows 10 which was released to public on October 1, 2014. It was released via fbl_release development branch of Windows 10. This build was referred as Windows 10 Technical Preview build.

Following were the important changes and new features in this build:

  • Addition of Start Menu which can be replaced by Start Screen using Taskbar Properties [Link]
  • Modern (metro) apps run in windowed mode on Desktop
  • Improvements to Snap feature with addition of Snap Assist
  • New Task View feature to quickly switch between running programs
  • Addition of Search and Task View buttons on Taskbar
  • Multiple (or Virtual) Desktops feature to add more than one Desktop screen
  • Improvements to Windows Explorer such as display of recent files and frequently visited folders in new Home view [Link]
  • Improvements to Command Prompt [Link]
  • Charms Bar disabled [Link]
  • Improvements to Internet Explorer
  • Metro IE (Immersive Internet Explorer) app removed
  • Some new icons

Windows 10 Build 6.4.9860 Changelog:

Windows 10 build 9860 was released on October 21, 2014 via fbl_release branch.

  • Addition of Windows Phone style Notification Center or Action Center (How-to disable guide)
  • Addition of new animation while switching between multiple Desktops
  • Addition of Data Sense and Battery Saver options in PC Setting app
  • New option to select Slow or Fast ring of Windows 10 builds download in PC Settings app
  • Addition of new zPC Settings app for testing purposes

Windows 10 Build 6.4.9879 Changelog:

Windows 10 build 9879 was released on November 12, 2014 via fbl_release branch.

  • New built-in options in Taskbar context menu to show/hide Search and Task View buttons [Link]
  • 3 dots menu replaced by Hamburger-style (3 lines) menu in metro apps titlebar
  • Ability to pin favorite folders to Home in File Explorer
  • Improvements to Internet Explorer
  • New Storage Sense option added in PC Settings
  • Hidden Continuum feature which was very buggy
  • Popup messages in metro apps are windowed now
  • Important changes in OneDrive such as use of selective sync
  • New updated animations
  • Some new icons
  • New horizontal battery indicator icon in Taskbar
  • New 3-finger gestures for precision touchpads
  • Native support for MKV and H.265 HEVC

Windows 10 Build 10.0.9926 Changelog:

Windows 10 build 9926 was released on January 23, 2015 via new fbl_awesome branch.

  • New improved Start Menu developed in XAML
  • Cortana enabled on Desktop (How-to disable guide)
  • New Tablet Mode (aka Continuum)
  • New Settings app
  • New Notification Center (or Action Center)
  • New Modern (Metro) apps such as Photos, Maps, Xbox
  • Windows Store beta added
  • Progress bar is shown while downloading Preview Builds
  • Improvements to ALT+Tab user interface and functionality
  • New full screen button added in Modern app titlebar
  • Improvements to Internet Explorer F12 Developer Tools
  • Charms Bar removed
  • New icons and animations

Windows 10 Build 10.0.10041 Changelog:

Windows 10 build 10041 was released on March 18, 2015 via new fbl_impressive branch.

  • New setup/installation UI
  • Transparent Start Menu
  • New icons and improved UI in Start Menu
  • New Login Screen
  • Minor changes to startup/shutdown screens
  • New improved Task View (Virtual Desktops) interface
  • Smaller Windows logo on Start button
  • New Network fly-out from Taskbar
  • Date is also visible in small Taskbar
  • Cortana is available for more locales
  • Updated apps
  • New icons

Windows 10 Build 10.0.10049 Changelog:

Windows 10 build 10049 was released on March 30, 2015 via fbl_impressive branch.

Windows 10 Build 10.0.10061 Changelog:

Windows 10 build 10061 was released on April 22, 2015 via fbl_impressive branch.

  • Transparent and dark Start Menu and Taskbar
  • Start Menu is now resizable
  • Power button moved to bottom-left corner in Start Menu
  • Transparency in Start Menu can be disabled
  • Start Menu and Taskbar color can be changed
  • Improvements to Project Spartan web browser
  • Improvements to Continuum aka Tablet mode
  • Improvements to Virtual Desktops (Task View)
  • "Screen resolution" option renamed to "Display settings" in Desktop context menu which now opens Settings app
  • New Calendar fly-out from Taskbar
  • New option to validate settings upon exit in TCP/IP settings
  • Some new metro (modern) apps
  • Some updated apps
  • Some new icons

Windows 10 Build 10.0.10074 Changelog:

Windows 10 build 10074 was released on April 29, 2015 via fbl_impressive branch. Since the release of build 10074, Microsoft started calling the testing builds as Insider Preview builds instead of Technical Preview builds.

  • Return of Aero Glass transparency with blur effect in Start Menu and Taskbar [Link]
  • New animation for live tiles in Start Menu
  • New sound scheme which is also set as default
  • Improvements and UI changes in Continuum (or Tablet Mode)
  • Improvements to Task View, Snap Assist and Alt+Tab screen
  • Improvements and UI changes in Cortana
  • Improvements to Windows Store beta
  • Personalize option in Desktop context menu now opens Settings app
  • Some UI changes in Settings app
  • Some updated apps

Windows 10 Build 10.0.10122 Changelog:

Windows 10 build 10122 was released on May 20, 2015 via fbl_impressive branch.

  • Improvements to Start Menu
  • Removal of Full Screen (Expand) button from Start Menu which was used to switch between Start Menu and Start Screen
  • Improvements to Continuum (or Tablet Mode)
  • Improvements to Project Spartan web browser including addition of New Tab page
  • Improvements to default filetypes handler program
  • Improvements to user interface

Windows 10 Build 10.0.10130 Changelog:

Windows 10 build 10130 was released on May 29, 2015 via fbl_impressive branch.

  • Improvements to Start Menu
  • New customization options for Start Menu in Settings app -> Personalization -> Start
  • Improvements to Continuum aka Tablet mode
  • Improvements to Project Spartan web browser
  • New keyboard shortcut WIN+C to launch Cortana
  • New UI for Jumplists in Taskbar
  • New Taskbar settings for Virtual Desktops in Settings app -> System -> Multitasking -> Virtual Desktops
  • New Taskbar animations for events like moving files, downloads, etc
  • Improvements to UI of Action Center (aka Notification Center)
  • New and updated icons set
  • Some updated apps
  • Some changes in user interface

Windows 10 Build 10.0.10158 Changelog:

Windows 10 build 10158 was released on June 29, 2015 via fbl_impressive branch.

  • Project Spartan web browser renamed to Microsoft Edge
  • Improvements to Microsoft Edge web browser
  • Lots of changes in user interface including new animations
  • Improvements to Cortana including new dark theme

Windows 10 Build 10.0.10159 Changelog:

Windows 10 build 10159 was released on June 30, 2015 via fbl_impressive branch.

  • Addition of new Hero wallpaper [Link]
  • Improvements to Login Screen including addition of Hero wallpaper as background image

Windows 10 Build 10.0.10162 Changelog:

Windows 10 build 10162 was released on July 02, 2015 via fbl_impressive branch.

  • Improvements to reliability, compatibility, performance and battery usage

Windows 10 Build 10.0.10166 Changelog:

Windows 10 build 10166 was released on July 09, 2015 via fbl_impressive branch.

  • New Microsoft Wi-Fi app to purchase paid Wi-Fi through Windows Store

Windows 10 Build 10.0.10240 Changelog:

Windows 10 build 10240 was released on July 15, 2015. Unlike previous Preview builds, this new build arrived via a new branch "TH1" (ThresHold1). TH1 development branch contains Windows 10 RTM candidate builds. So this new build 10240 was actually the final RTM build.

  • No watermark (or build number) on Desktop. You can still know the build number using winver command
  • Performance improvements to Microsoft Edge web browser

This build was released to public as Windows 10 RTM on July 29, 2015.

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That's all for now. We have tried to cover all important and worth to mention changes and new features present in each Preview build of Windows 10 till RTM build. If you know about any other important feature or change which was left to mention in this article, feel free to share it in your comment and we'll add it to the list.

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Posted in: Windows 10

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  • Thanks VG, is there any news about the integration of classic theme in Windows 10 ?

  • VG

    ^^ No. Forget it. ;)

  • VG, do you know if Windows 10 Insiders will once again have access to ISOs to do clean installs with anytime soon?

    Also, would updating the BIOS on the motherboard affect my activated copy of Windows 10?

    Thank you very much!

  • Hey!, I found a thing something strange in the Windows 10 Build 10240 registry. The NT version stills 6.3

    Find it on HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

  • VG, After up gradation of Windows 10 from windows 8, can windows provide me fresh windows key or I am continuing to use my windows 8 key for fresh standalone windows 10 installation.

  • VG

    ^^ Its still unknown. Only time will tell.

    Its not necessary to increase the kernel number. Although they can update it in final RTM build.

    @Michael Jackson
    Not until RTM release. Regarding updating BIOS, it should not affect the activation.

  • As per the below link, MS confirms that Build 10240 is RTM Version which is going to be out on July 29, 2015 for public availability. But your website says this build is a Pre-RTM build. Can you please confirm??


  • VG

    ^^ Yes. 10240 is the RTM build which will be given to public.

  • Hello Vishal,
    I am now running on genuine Windows 8.1 & is planning for W10 update. Can you make a brief tutorial about the backup process & tips to be considered before update?
    Also, my C drive is currently having only 7GB space left, will that be enough for entire upgrade process? It would be great if you could give a reply.....!

  • VG

    ^^ You should try to make more free space if possible. Try following:

  • Even Paul Thurrott, who by the time when Microsoft sent to Insiders the build, it was not sure that the build was actually the RTM. these days he states that the build 10240 is the build that Microsoft sent to OEM partners. It may not be RTM like in the old days because of "Windows as a Service" paradigm, but it is the the build people will receive on 29th of Jully.

  • I had reserved Windows 10 via the Get Windows 10 app. But when I am notified to upgrade, I see that the date indicated during the installation process is July 23. Not July 29. Should I continue. I am aware that there are two Windows 10 upgrade paths, one for a permanent license and another for a temporary license that expires once the Insider program ends. The aim is to get the permanent license. What should I do?


  • Dear VG

    As allways thank you for keeping us updated

    Just installed build 10525
    Works like a dream ( good dream, not a nightmare, not an american dream :P)
    Now we can change colors on title bar, looks much better
    Upgrade performed well and faster then previous ones, just under 40 minutes, including updates

    question: can I install this on my regular OS, win 10 home?
    or else, any idea when this will not be an evaluation but a definite upgrade

    thank you again

    Yours truly
    Peter Alexander London

  • VG

    ^^ You should not install it on your primary computer as these testing builds contain bugs and issues. Don't worry, all these builds will be offered to Windows 10 RTM users via Windows update in form of short updates soon.

  • Hey Vishal, did you notice the toggle for "When i resize a snapped window, simultaneously resize any adjacent snapped window" in Settings > System > Multitasking @ build 10547? It does what it said, show the tablet mode split screen while rezing two side by side window in desktop mode!

  • VG

    ^^ Yes. I have added it to the list. :)

  • @VG Nice!

  • I would like Microsoft to remove Control Panel and merge all the Control Panel settings to the Settings app in future versions? Also I would like an option to have a shut down down and have a start up sound like Windows XP and Windows 7.

  • Hey Vishal, i've noticed that Microsoft has re-enabled the use of VisualElementsManifest.xml for Win32 apps (use of custom tiles) e.g Google Chrome in 10565!

  • hi,
    thanks for this list.

    i have all the factory install dvd's (using esd-decrypter for install.esd) since insider started - except 9860 (sadly) - and one that's not on your list. 10125 dated may 17 2015 (that date 'could' be off a day or two). i can't tell you feature differences but i thought you'd like to know.


  • After installing Build 10.0.14295 I cannot access the "Store" and half of my apps are at a "pending" status. Help!

  • This article states that "Windows 10 Build 6.4.9841 Changelog:
    It was the first Preview build of Windows 10 which was released to public on September 30, 2014. It was released via fbl_release development branch of Windows 10. This build was referred as Windows 10 Technical Preview build."

    A member of a forum that I frequent disagrees with the date given.

    So was it September 30, 2014 or was it October 1, 2014?

  • VG

    ^^ Actually both dates might be correct. It depends upon the region. In some countries, the day was September 30 and in some countries it was October 1st.

  • Which OS is faster?

    I tested on a netbook (slower hardware) to see more clearly which OS is faster.
    To this netbook, I added 2GB RAM + 120GB SSD.
    (Clean install, no added apps during testing)

    1) Windows 7: Power on to usable desktop & wifi = 80s. Shutdown = 14s
    2) Windows 8: Power on to usable desktop & wifi = 20s. Shutdown = 9s
    3) Windows 10: Power on 2 usable desktop & wifi = 40s. Shutdown = 16s

    8 was 4x faster booting than 7, & 2x faster booting than 10.

    10 has various bugs, couldn't disable Cortana or updates without jumping through hoops (bad for privacy & for systems on limited web). Additionally, 10 had problems with various programs I tested it with.

    Metro was more baked in with 30+ Metro Apps being unable to be removed "because they are critical apps needed by Windows". Nonsense! When is Metro mandatory? They just want you to use the Apps store!!!

    Windows 10 just isn't ready to be used yet.
    It looks more like someone put an etch-a-sketch on top of an "OS" & designed it with rough edges.

    When you get using Windows 10 a lot, you find out that there are lots of things that don't work, or don't work right.

    For example: Edge browser. I tested various aspects of it & found that many of the HTML5/CSS3/Acid 3 & other tests came out identical. Absolutely identical, to the Internet Explorer that is included. There were 1 or 2 tests where it came out (barely) faster than IE, perhaps in V8. But, the improvement was so minimal that Edge could just be called IE 12.

    Additionally, Edge seemed to crash 2-4x times more than IE.
    IE crashes around 20x tabs while you can open hundreds in Chrome/Firefox being only limited by the RAM you have.

    Edge just seemed to crash around 5-10x tabs open or so, & just isn't ready.

    10 is not ready for prime time yet.

    Out of 50+ browsers tested, Chrome is about the fastest you can get in most situations. Certainly on slower & older netbooks because Chrome supports 3D on those devices. Firefox is perhaps the second fastest, but it has a block list so 3D won't work on your netbook. Meaning, Chrome is up to 30x faster on games/3D content than Firefox. Chrome = 30-60fps vs Firefox around 1-5fps.

    Now, on modern hardware, Firefox can beat Chrome in V8 (raw speed), CSS3 (page layout) but Chrome beats Firefox in HTML5 (modern web), 3D (2x faster in many cases), & while using on older hardware such as netbooks, feels around 4x faster.

    Firefox can get bogged down if you are a rapid typer where Facebook cannot keep up with your messages you are typing so you have to wait a moment or two for the words you type to appear on the screen. This happens despite using it in Windows 8 (Fastest tested OS for a netbook) & despite using ABP (AdBlockPlus) to speed things up by killing ads.

    With Chrome, your messages are about as fast as you can type & seems to keep up most the time without any delay.

    Windows 8 + Chrome is about as fast as you can get. There is 1 browser that may in some situations have the edge (but only very slightly) over Chrome. And, that is SlimJet. But, I prefer the simplicity of Chrome & to me there is not much difference. Some say it makes a difference on their system... Who knows?

    I have tried 200 something Linux distros on the netbook, to try to get a feel for how fast they are. Most are junk, cluttered interfaces, don't support networking (wifi) properly etc. There were a few that caught my eye, however. Puppy Linux would run apps instantly. Even on a netbook. Because of loading things directly to RAM, bypassing using the HDD/SSD.

    But, I didn't like the looks of Puppy Linux.
    Perhaps future versions will improve, but liked the speed.

    Linux Mint was a good looking OS, but it crashed on trying to do external larger monitor. Yes, the 17.3 Cinnamon desktop version of Linux Mint. One of the more beautiful Linux distros, but maybe they will fix that bug later. Seemed to run slower than Windows 8 on the netbook, so not a good option at the moment, for me.

    Lubuntu is an ok looking Linux, but it didn't seem to perform any better than Linux Mint, but some say it works better on low ram systems. Still seemed slowish on the netbook. Hoping it supports SSD. Don't know if that could have been a problem? Used latest available which was the 15x series.

    Xubuntu looked almost Windows 7ish. One of the best Linux alternatives to Windows, if you want a Windows 7ish start menu. However, it also ran a little sluggish on my netbook. Modern hardware, these Linux probably run great. But, I was a little disappointed in netbook performance.

    Peppermint, Elementary OS, Linux Mint, Lubuntu, Xubuntu, Puppy Linux.
    Those were the ones who caught my eye most.

    Most others were junk because of verrrrrryyyyyy slow compared to one of the above, though some of them probably worked ok on modern hardware. I think Debian was one that worked ok, but seems that it was similar to one of the Linux I listed above, so, didn't put it in the list.

    Windows 10 just isn't ready to be used commercially (yet).
    Windows 8 is about the fastest there is, for most people.
    Windows 8 + Chrome is about the fastest OS + Browser you can have.

    Windows 8 auto configures things for SSD that you have to manually configure under Windows 7, so even though Windows 7 is the 1st MS OS to support SSD, Windows 8 automatically disables System Restore, Prefetch, & other things when it detects SSD.

    Windows 8 uses fewer resources (Ram, etc) than Windows 7, even if you tweak 7 & disable services, startup items, & other things.

    Windows 8 runs faster, smoother, & includes useful features such as being able to natively load ISO files as virtual drives (run apps without needing extraction from the ISO, view the content of ISO, & other things).

    File copy is much improved & the pause/resume, combining multiple copy windows into 1 is very handy also.

    Windows 8 + Classic Shell (Adds Windows 7ish start menu) + Chrome.
    That's about all you need, really...

    Just make sure you go into ClassicShell options & disable the metro charms under Windows 8 tab.

  • Build 9841 was released for Download on 1 Oct 2014. NOT 30 Sept 2014. YOU HAVE IT WRONG and needs to change. Check with MSFT to confirm.

  • VG

    ^^ As I said in my earlier comment it depends upon region. In some region the day was Oct 1st and in other regions the day was Sep 30th. Anyway I have updated the article. Thanks. :)

  • I'm in neck deep trouble. I'm on the insider preview version 14342. Windows says I need to update my system before 17th of July or it'll restart every few hours (something that I did not see being mentioned anywhere). Every time I try updating, windows gives a different error such as system image is not signed properly etc. I saw a tool that allows insiders to go back to public version but that says it cannot work my system. This is my daily driver. How can I go to a public version?

  • VG

    ^^ Its a known issue. Here is what Microsoft says about it:

    If you are seeing a notification pop-up once a day that started on July 7th saying that your Windows evaluation copy expires on July 15, 2016, don't worry - this is a superfluous dialog and your OS won't expire. The dialog will also go away soon.

  • 14393.0. is last build from rs1 Branch.
    Are you going to add the ZDP Builds (Zero Day Patch) to this list ?
    So Far.

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