I can't turn on telemetry data

Remove the local diagnostic-data policies that are locking the switch, restart Windows, and then enable Send optional diagnostic data again.

Reset only the affected policies

The disabled switch and “Your organization prevents…” banner indicate that Windows is reading a diagnostic-data policy. Such a policy can remain on a personal PC without any work or school account. Optional diagnostic data is required for receiving Insider Preview builds.^1^

Windows 11 Pro, Enterprise, or Education

1. Press Win+R, enter gpedit.msc, and press Enter.
2. Go to: Computer Configuration > Administrative Templates > Windows Components > Data Collection and Preview Builds
3. Open Allow Diagnostic Data and select Not Configured.
4. Open Configure diagnostic data opt-in settings user interface and select Not Configured.
5. Select Apply > OK, then restart the PC.

These are the policies that control the diagnostic-data level and whether the Settings interface can change it.^2^

After restarting, open:

Settings > Privacy & security > Diagnostics & feedback > Diagnostic data

Turn on Send optional diagnostic data, restart once more, and check Settings > Windows Update.^1^

Windows 11 Home, or if Group Policy shows both settings as Not Configured

Use an elevated Terminal to back up the relevant policy key and remove only the two values that control telemetry and its Settings interface.

This changes the registry. The export command creates a backup before anything is removed.

1. Right-click Start and select Terminal (Admin).
2. Run:

reg export "HKLM\SOFTWARE\Policies\Microsoft\Windows\DataCollection" "%USERPROFILE%\Desktop\DataCollection-backup.reg" /y
reg delete "HKLM\SOFTWARE\Policies\Microsoft\Windows\DataCollection" /v AllowTelemetry /f
reg delete "HKLM\SOFTWARE\Policies\Microsoft\Windows\DataCollection" /v DisableTelemetryOptInSettingsUx /f
shutdown /r /t 0

An error saying a value was not found is harmless. Microsoft documents AllowTelemetry under this registry path; value 3 represents optional diagnostic data, while the opt-in UI policy determines whether users can adjust the level.^2^^3^

After the restart, enable the switch in Settings > Privacy & security > Diagnostics & feedback. Microsoft confirms that unavailable options accompanied by the organization message mean the setting is policy-managed.^4^

If the policy returns or the switch remains locked

A privacy, debloating, telemetry-blocking, or security utility can reapply the policy. Disable its telemetry-policy feature before repeating the targeted reset; otherwise the values may be recreated.

Because this PC was previously enrolled in Insider, stale WindowsSelfHost state is another applicable fallback. A closely matching case involving the same message and the 26300 build family was resolved by deleting that key so Windows could rebuild it.^5^

Back it up and reset it:

reg export "HKLM\SOFTWARE\Microsoft\WindowsSelfHost" "%USERPROFILE%\Desktop\WindowsSelfHost-backup.reg" /y
reg delete "HKLM\SOFTWARE\Microsoft\WindowsSelfHost" /f
shutdown /r /t 0

Then enable optional diagnostic data and, if needed, reselect the Insider channel under Settings > Windows Update > Windows Insider Program. Do not delete the entire HKLM\Software\Policies tree; that is much broader than necessary.

This telemetry symptom is not currently listed as a Windows 11 26H2 known issue, so resetting the local policy state is preferable to treating it as a build-wide defect.^6^

References

1. Choosing your data settings
2. Windows Error Reporting and Windows diagnostics enablement guidance
3. Policies (Windows Configuration Designer reference)
4. Diagnostics, feedback, and privacy in Windows | Microsoft Support
5. Cannot change turn on optional diagnostic data to update Windows Insider Program - Microsoft Q&A
6. Windows 11, version 26H2 known issues and notifications