Microsoft released KB5124010 on September 22, 2026, giving Windows 11 users an early look at what is coming in October’s official update. This one is optional, not mandatory, and it brings a handful of small but genuinely useful changes. Here is everything it includes and how to install it if you want to try it early.
Quick Answer
- KB5124010 is a preview (optional) update for Windows 11, released September 22, 2026
- It moves 25H2 to build 26200.9550 and 24H2 to build 26100.9550
- Main additions: Copilot key remapping, auto-maximize apps, new touchpad gestures, and File Explorer preview improvements
- This is the last preview update version 24H2 will receive, since 24H2 Home and Pro reach end of support on October 13, 2026
- You can install it now through Windows Update, or simply wait for the official October update
What’s New in KB5124010
Remap the Copilot key
If your keyboard has a dedicated Copilot key, you can now assign it to a different function instead, useful if you rarely use Copilot but have a key sitting there doing nothing else.
Auto-maximize apps
A new option lets certain apps open in a maximized window automatically, instead of opening in whatever size they were last used at.
New touchpad gestures
More gesture controls have been added for precision touchpads, giving laptop users a few more ways to navigate without touching the trackpad’s edges or buttons.
File Explorer preview pane changes
This is a subtle but practical one. Previously, previewing an HTML file in File Explorer’s preview pane came with a security warning every time. Now, you get a clear Preview anyway button to acknowledge the warning and proceed. Non-HTML files, like PDFs, now preview automatically without needing to click through anything.
Emoji 17.0 support
Windows 11 now supports the latest emoji set.
New Tips widget
A small widget has been added that surfaces tips for getting more out of Windows.
WinRE Wi-Fi profile reuse
If your PC needs to enter the Windows Recovery Environment, it can now reuse previously saved Wi-Fi profiles automatically, instead of asking you to reconnect manually during recovery.
Bluetooth fixes
Microsoft included a batch of Bluetooth-related bug fixes in this release as well.
Remote management support
IT administrators managing devices through MDM (Mobile Device Management) tools get expanded remote management support with this update.
Is This a Mandatory Update
No. KB5124010 is a non-security preview update, meaning it is entirely optional. These preview updates exist so Microsoft can test upcoming features on real devices before rolling them into the official monthly release. If you would rather wait, all of these changes will arrive again as part of October’s regular Patch Tuesday update, which is mandatory.
Why This Matters More for 24H2 Users
If you are running Windows 11, version 24H2, this is worth noting: KB5124010 is the last preview update that 24H2 will receive. Since 24H2 Home and Pro editions reach end of support on October 13, 2026, Microsoft is winding down preview releases for that version. If you have not yet moved to 25H2, now is a good time to do it through Settings > Windows Update.
How to Install KB5124010
- Go to Settings
- Click Windows Update
- Click Check for updates
- If it does not appear automatically, since this is a preview update, you may need to turn on Get the latest updates as soon as they’re available under Windows Update > Advanced options
- Once visible, click Download and install
How to Check If It’s Installed
Go to Settings > System > About and check your OS Build number. You should see:
- 26200.9550 on Windows 11, version 25H2
- 26100.9550 on Windows 11, version 24H2
Frequently Asked Questions
What is KB5124010?
KB5124010 is an optional preview update for Windows 11, version 25H2 and 24H2, released September 22, 2026, ahead of the official October 2026 update.
Do I need to install KB5124010?
No, it is entirely optional. Everything included in it will be part of October’s mandatory Patch Tuesday update as well.
What’s new in KB5124010?
Copilot key remapping, an option to auto-maximize apps, new touchpad gestures, improved File Explorer previews, Emoji 17.0, a new Tips widget, and Bluetooth fixes.
Why isn’t KB5124010 showing up for me?
Preview updates require an extra setting turned on. Go to Settings > Windows Update > Advanced options and enable “Get the latest updates as soon as they’re available.”
Is this the last update for Windows 11 24H2?
It is the last preview update for 24H2. The version will still receive its regular mandatory security updates until Home and Pro editions reach end of support on October 13, 2026.
What build number does KB5124010 bring?
It moves 25H2 to build 26200.9550 and 24H2 to build 26100.9550.
