Where this build sits
The 26H1 name causes a lot of confusion, so it's worth starting there. Microsoft's Flight Hub describes Windows 11, version 26H1 (Build 28000) as not a feature update for version 25H2. It contains platform changes for specific silicon and needs no action from customers. Beta (26H1) builds sit on top of Build 28000, and an enablement package raises the number to 28020. Experimental (26H1) builds use 28120 instead. Flight Hub lists 28020.3445 alongside Experimental (26H1) build 28120.3454, both dated November 6.
BetaWiki's tracking adds hardware context. It says this version ships only on new devices using the Qualcomm Snapdragon X2 and Nvidia RTX Spark (N1X) system-on-chip platforms. Microsoft has also said that devices running Windows 11, version 26H1 will not be able to update to version 26H2. Instead, they'll have a path to update to a future Windows release. The reason, per Microsoft, is that version 26H1 is based on a different Windows core than Windows 11, versions 24H2, 25H2, and 26H2.
Microsoft's release notes don't give a KB number. Comss.ru, a Russian Windows news site, reports that Microsoft released cumulative update KB5132091 (Build 28020.3445) for Windows 11, version 26H1 for Insiders in the Beta channel. Treat that number as third-party reporting rather than something Microsoft has stated.
This build also does more than recent releases on the branch. Windows Report called Build 28020.3172 from early October mainly a maintenance update rather than a release packed with new functionality.
Section summary: Build 28020.3445 is a Beta (26H1) flight for a Windows branch built for specific new silicon. It is not a 25H2 feature update, and it brings several user-facing features at once.
Windows Search moves to WinUI 3 and gains inline actions
The main change is a new Windows Search built on WinUI 3, which is beginning to roll out to this channel. Microsoft says it is faster, uses fewer resources, and has a simpler layout that makes results easier to scan. Inline actions let you do things straight from Search:
- Turn on dark mode or Bluetooth
- Adjust screen brightness
- Mute the device
- Arrange windows
Search is also getting better at matching typos and synonyms, and Microsoft says it will keep tuning that over the coming weeks. English is the only supported language for this first release.
Beta (26H1) users are not the first to see this. Microsoft introduced it on October 7 in the Experimental and Experimental (26H1) channels. That announcement explains the redesign: almost all clicks in the old interface landed on the results list on the left, not the large preview pane on the right, so Microsoft merged results into a single list. The same post suggests phrases to try, such as "switch to dark mode," "turn on night light," "dim my screen," "mute," and "minimize all my windows." It also says actions for Phone Link-connected phones are coming soon.
Some limits from that announcement still apply:
- Taskbar only for now. Microsoft said early previews would keep the old search experience in the Start menu while it refines the new one. Bringing the new Search to Start is planned for next year.
- More is planned. Inline file previews, richer file details, rich web answers, and category filters were described as coming later.
- Feature flags were Experimental-only. In October, Experimental-channel Insiders could turn the feature on early under Settings > Windows Update > Windows Insider Program > Feature flags, after installing build 26340.9616 or 28120.3181. The Beta (26H1) release notes mention no such switch, so don't assume one exists on 28020.3445. If your device hasn't received the feature yet, you'll probably have to wait.
Microsoft's October post asked for feedback in Feedback Hub under Desktop Environment > Search.
Section summary: The new Search reaches Beta (26H1) in English only, on the taskbar, through a gradual rollout. Its inline actions put quick settings changes in the search box.
Magnifier now handles each monitor separately
The Magnifier changes are the most practical part of this release. Until now, Magnifier stretched one magnified view across every display, so zooming one screen zoomed all of them and the screen edges blurred together. Now each monitor keeps its own boundary and its own zoom level. Microsoft's example is 300% on a writing screen and 150% on a reference screen.
How to set it up
- Open System > Display and set your monitors to Extend, not Duplicate. Per-monitor behavior requires Windows to treat each screen as its own space.
- Per-monitor zoom is on by default, so there's nothing else to enable.
- Set the zoom for each screen in any of these ways:
- Move the pointer onto that screen and press Windows key + Plus (+) or Windows key + Minus (-).
- Hold Ctrl + Alt and turn the mouse wheel.
- Enter percentages directly under Accessibility > Magnifier.
- Drag the Magnifier toolbar onto a screen and use its on-screen controls.
- To go back to the old single zoom across all displays, turn per-monitor zoom off from the Magnifier toolbar or Accessibility > Magnifier.
If per-monitor zoom doesn't seem to work, first check whether your displays are set to Duplicate. That's the only prerequisite Microsoft lists.
Viewport locking
The magnified view follows your pointer, which becomes a problem when you're copying from a document on one screen into an email on another. Viewport locking fixes that:
- Point at the screen you want to hold and press Ctrl + Windows key + K. An on-screen message confirms the lock.
- The locked screen stays live and interactive. You can still click it, read it, or copy from it, but its view won't move.
- Press Ctrl + Windows key + K again while pointing at that screen to unlock it.
- Press Windows key + Esc to release all locks at once.
- If the shortcut conflicts with something else, you can change it to Ctrl + Alt + P under Accessibility > Magnifier.
A contrast theme as an alternative to inversion
Many people with glare sensitivity use color inversion, but inversion also distorts photos, charts, and video. The new contrast-theme toggle on the Magnifier toolbar recolors the interface and leaves media in its original colors. The dark theme is the default, and you can pick which contrast theme the toggle applies under Settings > Accessibility > Magnifier. Color inversion remains available and works as before.
Section summary: Magnifier now supports separate zoom per display, view locking, and a glare-reducing contrast theme that doesn't change media colors. Extend mode is the only setup requirement.
File Explorer: Preview pane changes for web downloads
The File Explorer note is a single line: PDFs and non-HTML files downloaded from the web can now be previewed automatically in the Preview pane. Microsoft doesn't say which non-HTML file types are included or whether any settings are involved.
Admins should look at this one carefully. Preview handling for downloaded files is closely tied to Mark of the Web protections. Before generalizing the change, test which file types actually render on a 28020.3445 device. That's general industry caution on our part, not something Microsoft's notes address.
Who should care, and how much
- Accessibility users with more than one monitor: The Magnifier work is the reason to watch this build. Per-monitor zoom and viewport locking address real problems people run into every day.
- Search enthusiasts: You get the WinUI 3 Search here, but Experimental channel users got it a month earlier and will likely get later additions first.
- IT pros: Because 26H1 is tied to specific silicon and has its own upgrade path, these builds mostly matter for planning around Snapdragon X2 and N1X hardware. They don't predict what your 25H2 fleet will get.
The usual Insider caveats apply. Microsoft says features in these builds may change, be removed, or never ship beyond the Insider program, and that localization may be incomplete. Report localization issues through Feedback Hub. The desktop watermark is expected on preview builds, and Flight Hub shows which build is in which channel.
If you're testing 28020.3445, share what you find with other WindowsForum readers in the Windows Insider builds and accessibility threads. Results from people using Magnifier on mixed-resolution, multi-monitor setups would be especially useful.