Pretty Unstable Since install of 26220.9739

A PC on build 26220.9836 can move to released Windows 11 25H2 with an in-place installation that keeps files and applications, so a destructive clean install is optional rather than required.

Preserve evidence before changing builds

The retrieved release notes for builds 26220.9739 and 26220.9836 do not list a known issue specifically describing hard locks or freezes; that does not rule out a build, driver, firmware, or hardware-specific regression.^1^^2^

Before reinstalling:

1. Press Win+F to open Feedback Hub.
2. Search for reports containing 26220.9739 freeze, 26220.9836 hard lock, and relevant hardware details. Upvote a matching report or select Give feedback > Report a problem.
3. Include when the lock occurs, whether audio loops, whether the pointer moves, and whether the keyboard LEDs respond.
4. If there is a predictable trigger, start Record my problem immediately before it. Do not repeatedly force a freeze; a complete lock may prevent the recording from being stopped and saved normally.^3^

Move to released Windows 11 25H2 without wiping

First make a current backup. Also record the installed edition and system language, because the installation media must match them.

1. Open Settings > Windows Update > Windows Insider Program > Stop Insider Preview Builds.
2. Enable the option to stop receiving preview builds. Microsoft documents this exit path for Beta-channel devices.^4^
3. Download a released Windows 11 25H2 ISO matching the installed language and edition.
4. If the device remains enrolled after using the supported Settings option, the case-matched 26220.xxxx procedure is:
   • Open Registry Editor as administrator.
   • Navigate to:

          HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsSelfHost
     

   • Export that key as a backup.
   • Delete WindowsSelfHost, close Registry Editor, and restart.
   Registry deletion changes Insider enrollment state; export the key first and do not delete its parent keys. This procedure is specifically documented in the Q&A resolution for 26220.xxxx builds.^5^
5. Right-click the released ISO and select Mount.
6. Open the mounted drive and run setup.exe from inside Windows—do not boot from the media.
7. Select Change what to keep > Keep personal files and apps, then start the installation.

An in-place installation preserves personal files, installed applications, and settings. Confirm that Setup offers Keep personal files and apps before proceeding; if it does not, cancel and recheck the ISO language and edition.^6^

If a clean installation is still preferred

A clean installation is reasonable if the objective is to eliminate accumulated software and configuration state. It removes files, applications, settings, and manufacturer customizations.^6^

Before starting:

• Back up all required files and application data.
• Confirm Windows activation and install the same licensed edition.
• Save the BitLocker recovery key if encryption is enabled.
• Disconnect secondary drives to reduce the risk of deleting the wrong disk.
• Boot from the installation USB, select Install Windows 11, and delete partitions only on the intended Windows disk.
• Install drivers and firmware from the PC or component manufacturer after Setup completes.

If the hard locks continue on released Windows after a clean installation—particularly before third-party applications are restored—the Insider build is no longer the only plausible factor. At that point, investigate firmware, storage, memory, GPU, power, and other hardware-specific causes rather than repeatedly reinstalling Windows.

References

1. Announcing new builds for 16 October 2026 - Windows Blog
2. Announcing new builds for 30 October 2026 - Windows Blog
3. Deeper look at feedback
4. Troubleshooting
5. leaving the insider program - Microsoft Q&A
6. Reinstall Windows with the installation media