Windows 11 26H1 Cloud Rebuild: Beta vs Experimental Drive Sanitization and Remote Reset

The builds, and which channel gets which​

Microsoft's Windows Insider blog announced the October 2 batch as Beta (26H1): Build 28020.3142, Experimental (26H1): Build 28120.3151, and Experimental (Future Platforms): Build 29680.1000. Two mainstream builds came out the same day as well: Beta: Build 26220.9587 and Experimental: Build 26340.9596. This article covers only the two 26H1 builds.

Pureinfotech gives a short summary: Beta build 28020.3142 introduces Cloud rebuild, allowing Windows to reinstall itself from WinRE using the Windows image and drivers downloaded through Windows Update, and Experimental build 28120.3151 expands Cloud rebuild with drive sanitization and remote management capabilities for IT administrators.

Some background on 26H1, because the name suggests more than it is. Microsoft's Flight Hub describes 26H1 (Build 28000) as something that "is not a feature update for version 25H2". It only includes platform changes to support specific silicon. The preview builds sit on top of Build 28000 through an enablement package, which raises the number to 28020 for Beta (26H1) and 28120 for Experimental (26H1). Most people on a typical 25H2 PC won't be offered these builds, and that's expected.

Summary: There are two builds in two channels with overlapping changes. Cloud rebuild has now reached Beta (26H1). Experimental (26H1) gets the sanitize and admin features.

Cloud rebuild arrives in Beta (26H1)​

This feature has been moving through the channels for a while. According to Thurrott.com, Cloud Rebuild was first made available on the Experimental Channel in July, and last week, Microsoft made it available on the Experimental (26H1) channel. The feature is now available on today's Beta (26H1) Preview Build 28020.3142 as well.

The idea is simple. Windows Report explains that Cloud Rebuild can reinstall Windows 11 when the PC will not boot. Reset this PC rebuilds from the files already on the machine. Cloud rebuild has the recovery environment download both the Windows image and the device drivers from Windows Update. You don't need a USB stick made on another PC, or a recovery partition that might be as broken as the OS.

Before it starts, Windows shows the target build, edition and language, then warns you about data loss. Read that warning carefully. This is a full reinstall, not a repair.

How to start a Cloud rebuild on Beta (26H1)​

1. Check WinRE first. Microsoft's Cloud rebuild documentation says the device needs a healthy Windows Recovery Environment. You can confirm it's enabled by running reagentc /info from an elevated command prompt. Do this while Windows still boots.
2. Boot into WinRE. Windows Report gives the path for this build as Troubleshoot > Recovery and uninstall > Cloud rebuild. Microsoft's general documentation lists it as Troubleshoot > Cloud rebuild, so the exact menu may differ between preview builds.
3. Get online. WinRE supports Ethernet and Wi-Fi. Microsoft's troubleshooting guidance currently says only WPA-2 Personal Wi-Fi works in WinRE. If you're on an enterprise or WPA3 network, wired Ethernet is the safer choice.
4. Check the target build, edition and language, then accept the data-loss warning.
5. Keep the power connected and leave it alone. Microsoft warns that restarting or powering off while Cloud rebuild is preparing, downloading or installing can leave Windows unable to boot.
6. Finish setup. The PC boots into the out-of-box experience (OOBE). On Entra-joined, Intune-managed devices registered with Autopilot, Microsoft says Intune redeploys apps and policies, and user files come back through OneDrive after sign-in.

When it fails: error codes from Microsoft's documentation​

The last error shows the main dependency. Cloud rebuild only works if your hardware vendor publishes its drivers through Windows Update. If a custom-built PC uses an unusual NIC, keep your USB installer.

Summary: Beta (26H1) Insiders can now reinstall Windows from WinRE without separate media. It depends on a working WinRE, a supported network connection, Windows 11-eligible hardware and drivers available on Windows Update.

Experimental (26H1): sanitizing drives and remote rebuilds​

Build 28120.3151 makes Cloud rebuild more useful for handing off or retiring a PC. Windows Report says users now get two choices when preparing a rebuild: Remove files and Remove & sanitize files. Pureinfotech describes the sanitize option as a drive sanitization option for devices being recycled or reassigned, along with remote management support for network administrators.

Microsoft's documentation explains the difference:

• Remove files: The drives are reformatted and Windows is reinstalled. It's faster, but files might be recoverable with specialized recovery tools.
• Remove & sanitize files: Windows asks the storage hardware to securely erase the data before reinstalling. It takes longer depending on drive size and type, and shows "Sanitizing data" while the device may look idle.

Microsoft also adds a warning that anyone with compliance duties should read. Sanitization depends on the storage device supporting the erase command and implementing it correctly. Windows sends the request and reports the result the drive returns, but it cannot independently verify what the drive actually did. If you're retiring or transferring a device under a policy or regulatory requirement, Microsoft says to confirm support with the manufacturer and use a manufacturer-provided tool where needed.

For a personal laptop going to a family member, Remove & sanitize files is a big improvement over a plain reformat. For a fleet of laptops covered by data-disposal rules, treat it as one step in the process, not proof the data is gone. You'll still need the manufacturer's confirmation and your own documentation.

The admin side: Recovery CSP​

The second change is remote control. Windows Report says IT administrators can now configure and launch Cloud rebuild remotely through the Recovery CSP. They can target the current Windows version or a specified supported build. Microsoft's documentation says this works through an endpoint management tool such as Intune and lists these nodes under ./Device/Vendor/MSFT/Recovery/CloudRebuild/:

• EnableLocalRebuild: Allows or blocks rebuilding to the build currently installed. If it's disabled, the WinRE entry still appears, but users get an error page when they try it.
• EnableCustomRebuild: Allows or blocks rebuilding to a specified target build.
• Execute: The node that triggers the rebuild. Its child values are validated together, and nothing runs until the full configuration is valid. RebuildType is either LocalRebuild (other values ignored) or CustomRebuild. CustomRebuild requires BuildBranch, OSVersion, Edition, InstallationType (only Client is supported for now), SystemLanguage and LCUVersion. UnattendXML is optional.

There's a reporting limitation. The status node is only populated when a rebuild fails early, while the original OS is still reachable. If the rebuild succeeds, or fails after sanitization or repartitioning, admins need recovery remote-management plugins to track progress. Microsoft also notes the Recovery/CloudRebuild nodes exist only in Insider Preview builds and may change, and the whole feature is labelled for non-production evaluation.

On Wi-Fi: the 26H1 Experimental release notes from August 31 (Build 28120.2824) announced that WinRE can reuse eligible Wi-Fi profiles saved in Windows, including supported certificate-based networks. That would cover many enterprise Wi-Fi setups. The general Cloud rebuild troubleshooting page still lists WPA-2 Personal as the only supported Wi-Fi type. Test this in your own environment before assuming a remote rebuild will reconnect over corporate wireless.

Summary: Experimental (26H1) separates a normal wipe from a hardware-level erase and lets admins start rebuilds remotely. Both are preview features, and the sanitize option is only as reliable as the drive's firmware.

Magnifier: type an exact zoom level​

Accessibility users get a small but useful change in both builds. In the Beta build, Windows Report says users can now enter an exact zoom percentage directly from the Magnifier toolbar instead of repeatedly increasing or decreasing magnification. Microsoft has also added preset zoom increments ranging from 5% to 400%, making it faster to move between commonly used magnification levels. Windows Report describes the same exact-percentage entry and 5%–400% presets for Experimental Build 28120.3151.

If you've ever pressed Win + Plus over and over to reach a comfortable zoom, typing the number you want is a real improvement. Don't confuse this with the Magnifier change from late August. The 28120.2824 notes covered a toolbar refresh with updated icons and spacing, and Microsoft said at the time that zoom controls and shortcuts hadn't changed. The October builds are the ones that change how you set the zoom level.

File Explorer: consistency fixes in both builds​

Neither build redesigns File Explorer. Both fix small problems that come up constantly:

• Folder views stay put. Folder view customizations, including sorting preferences and icon sizes, should now remain more consistent when users access the same folders through different paths or applications.
• More forgiving address bar. Explorer now correctly handle paths containing double backslashes and quotation marks. This should improve compatibility when users paste paths created by different applications or tools. For example, a path copied from a script, an escaped string or a "Copy as path" result with quotes around it should now work when pasted.
  [*]Suggestions close properly. Microsoft fixed an issue where the address bar suggestion dropdown did not always close correctly after users selected an entry.
  [*]Rename fixes. Windows should no longer repeatedly select text while renaming files, while changes that only modify capitalization should now appear immediately across both local and cloud storage. Renaming example.txt to Example.txt should show the new capitalization without a refresh. Windows file systems are usually case-insensitive, so a capitals-only rename has often looked as though nothing happened.
  

Should you care yet?​