Microsoft has released another Windows 11 Insider Preview build for users testing the upcoming Windows 11 version 26H2 update.
This time, we’re taking a look at Windows 11 Build 26300.8935, which has been released to Windows Insiders in the Experimental channel.
While this isn’t one of those builds packed with huge headline features, there are actually quite a few useful changes underneath the surface — particularly around File Explorer performance, the taskbar, Widgets, desktop backgrounds, Windows Update and general usability.
So, let’s take a closer look at everything that’s new and improved.
🖥️ Windows 11 26H2 Build 26300.8935
Build 26300.8935 is part of Microsoft’s ongoing development of Windows 11 version 26H2.
Microsoft is continuing to test new features and refinements through the Windows Insider Program before they potentially make their way into the final public version of Windows 11.
As this is an Experimental channel build, it’s important to remember that some features may only be available to a limited number of users initially.
Microsoft often uses staged rollouts to test new functionality before gradually making it available to more Insider devices.
Some experimental features may also change significantly — or disappear entirely — before reaching the stable version of Windows.
📁 File Explorer Is Getting Faster
One of the biggest areas Microsoft has focused on in this build is File Explorer performance.
And considering how often we all use File Explorer, these are some very welcome improvements.
Faster File Deletion
Microsoft says File Explorer should now be faster when deleting certain large and heavily fragmented files.
This probably isn’t something you’re going to notice when deleting a couple of photos or documents, but users working with larger files could see a noticeable improvement.
It’s another small step towards making File Explorer feel more responsive.
Faster File Explorer Home
Microsoft has also improved the loading performance of the File Explorer Home page.
Opening File Explorer Home should now feel faster and more responsive than before.
File Explorer performance has been a fairly common complaint throughout Windows 11’s lifetime, so it’s good to see Microsoft continuing to work on reducing delays and improving responsiveness.
Touch Scrolling for Recommended Files
Another File Explorer improvement affects the Recommended section on the Home page.
If you’re using a touchscreen Windows device, you can now scroll through recommended files using touch.
It’s a fairly small change, but it should make File Explorer feel more natural on tablets, 2-in-1 laptops and other touchscreen devices.
🖼️ Desktop Background Improvements
Microsoft has also made improvements to how Windows handles your desktop wallpaper.
In Build 26300.8935, desktop backgrounds should now remain more consistent across different situations.
This includes users who make use of multiple virtual desktops.
Previously, there could be situations where Windows didn’t properly remember or apply the background you had selected.
Microsoft has now improved background persistence to help prevent that from happening.
There have also been some small cosmetic changes made to:
Settings → Personalization → Background
They’re not major redesigns, but they help bring the page more in line with the rest of the Windows 11 Settings experience.
🎨 More Animated Widgets
Widgets are also getting another update.
Microsoft is expanding support for animated icons on the Widgets button within the Windows 11 taskbar.
We’ve already seen Microsoft experimenting with animated weather and notification-related content in the Widgets area, but this latest update expands the range of dynamic content that can appear.
Supported widget providers may now be able to display more noticeable animated updates directly from the taskbar.
The idea is to make important or interesting information easier to spot without requiring you to actually open the Widgets panel.
Whether everyone wants more movement happening on the taskbar is another question — but thankfully Microsoft appears to still be testing how users respond to the experience.
▶️ Improvements to the New Run Dialog
Microsoft has also made a small improvement to the redesigned Run dialog.
If you’re using the newer Run interface, pressing:
F4
will now expand the suggestions dropdown for command completion.
This should make it slightly easier to quickly select previously used commands or complete something you’re entering.
The Run dialog is one of those parts of Windows that has remained relatively unchanged for years, so it’s interesting to see Microsoft continuing to modernise it alongside the rest of Windows 11.
📌 Taskbar Fixes
The Windows 11 taskbar receives several small fixes in this build.
Microsoft has addressed some visual problems that could occur when using the taskbar in an alternative position.
Microsoft has been experimenting with more taskbar positioning options, and as you’d expect from an experimental feature, there have been a few rough edges.
One particular issue caused Notification Centre to appear in the wrong location when the taskbar was positioned at the top of the screen.
That issue should now be fixed.
These might sound like relatively small problems, but they’re exactly the type of refinements Microsoft needs to make before features like this become ready for everyday users.
🔎 The Windows Search Box Is Slightly Taller
Here’s probably one of the smallest changes in the entire build.
Microsoft has increased the height of the taskbar Search box by 4 pixels.
Yes — four pixels.
It’s certainly not going to completely change your Windows experience, but it does make the search box slightly larger and could improve its visual alignment with other taskbar elements.
It’s one of those changes you might not immediately notice unless someone points it out.
🖱️ Mouse Cursor Improvements
Microsoft has also fixed a frustrating mouse-related problem affecting some Windows Insiders.
Some users had noticed that their mouse cursor would repeatedly blink or flicker after installing recent Insider builds.
Build 26300.8935 includes a fix for this issue.
Microsoft has also improved how Windows remembers your selected mouse cursor size.
If you’d previously changed the cursor size and found that Windows wasn’t consistently remembering the setting, that should now work more reliably.
🎤 Voice Typing Settings Should Now Stay Saved
Voice Typing also receives a small but useful reliability improvement.
Microsoft has improved the way Windows remembers settings relating to:
- Automatic punctuation
- Voice Typing launcher preferences
Previously, some users found that their chosen settings wouldn’t always persist properly.
Those preferences should now be remembered more reliably after installing this build.
🔄 Windows Update Error 0xc0000409 Fixed
One of the more important fixes in Build 26300.8935 relates to Windows Update itself.
Microsoft has fixed an issue which could cause recent Windows Insider builds to fail during installation with error 0xc0000409.
If you’ve been trying to install recent Insider updates and repeatedly running into this particular error code, this build should hopefully resolve the problem.
It’s especially important because installation issues like this can prevent Insider devices from moving onto newer builds entirely.
⚙️ Feature Flags Remain Important
As with many recent Insider builds, not every new feature is necessarily enabled immediately.
Microsoft continues to use Controlled Feature Rollout, meaning some features are initially released to a smaller group of Windows Insiders.
Microsoft then monitors feedback and reliability before gradually expanding availability.
If you’re using the Experimental channel and want to try some of Microsoft’s latest experimental features, you can also check:
Settings → Windows Update → Windows Insider Program → Feature Flags
Depending on your build and device, you may see additional experimental functionality that can be enabled from here.
💧 Don’t Worry About the Desktop Watermark
If you’ve installed Build 26300.8935 and noticed a Windows build watermark in the bottom-right corner of your desktop, don’t panic.
This is completely normal when running pre-release Windows Insider builds.
The watermark doesn’t mean your copy of Windows isn’t activated.
It’s simply there to indicate that you’re running a development version of Windows rather than a normal public release.
⚠️ Remember – This Is an Experimental Build
It’s worth stressing that this is still an Insider Preview release.
The Experimental channel is specifically designed for Microsoft to test features that may not yet be ready for the public.
That means features included in Build 26300.8935 could:
- Change before release
- Be redesigned
- Be temporarily disabled
- Only roll out to certain users
- Never appear in the final version of Windows 11
You may also encounter bugs or reliability problems that you wouldn’t normally expect from a stable Windows release.
For that reason, I wouldn’t recommend installing Experimental Insider builds on a computer you rely on for important work unless you’re comfortable troubleshooting potential problems.
🚀 Windows 11 26H2 Continues to Take Shape
Overall, Windows 11 Build 26300.8935 isn’t a massive feature update, but it does contain quite a few useful refinements.
The biggest improvements are definitely around File Explorer performance, which should now feel quicker when loading Home and handling certain large file operations.
The new Widgets animations, taskbar positioning fixes, improved desktop background reliability and Windows Update fix are also welcome additions.
It’s becoming increasingly clear that Microsoft is placing a lot of focus on polishing and improving the everyday Windows 11 experience rather than simply adding huge new features with every Insider release.
And personally, I think that’s a good thing.
Windows 11 already has plenty of functionality — improving the speed, reliability and consistency of the features we use every day can make just as much difference.
🎥 Watch the Full Video
I’ve also taken a closer look at Windows 11 26H2 Build 26300.8935 in my latest Matthew’s Techhub video.
In the video, I go through the latest changes and show you what’s new inside the build.
If you’re currently testing Windows 11 26H2, let me know what you think of these latest changes.
Have you noticed File Explorer feeling faster, and what would you like Microsoft to improve next?
As always, make sure you’re subscribed to Matthews Tech Hub for more Windows 11 news, Insider builds, tutorials and tech content.
