How to Edit the registry on WinPE

1. Mount the WinPE.

2. Run regedit and select the HKLM hive.

3. Select File | Load Hive, then browse to the location of your Windows PE build. Select Software mount\windows\system32\config.

4. Enter a temporary name for the hive like WINPE.

5. Edit the registry as normal.

6. Select File | Unload Hive... and confirm the Yes | No dialog, and ensure you dismount the registry every time, as having it locked will prevent a successful build of Windows PE.

7. Quit Regedit.

8. Unmount

HKLM\Software\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell
ExecutionPolicy = Unrestricted