Windows 11 update error encountered when upgrading from Windows 10

Yeah, I ran into that same Windows 11 update error (0x80888002) once — it usually pops up when the installer can’t verify TPM or Secure Boot properly.

Here’s what fixed it for me:

1. Open regedit, go toHKEY_LOCAL_MACHINE\SYSTEM\Setup\MoSetup
2. Create a new DWORD value:AllowUpgradesWithUnsupportedTPMOrCPU = 1
3. Save, close, then rerun setup.exe from your Windows 11 ISO.

That bypasses the check and the Windows 11 update error disappears. Everything upgraded fine afterward.

Here’s a solid Microsoft link you can cite along with the fix:
🔗 https://learn.microsoft.com/en-us/answers/questions/4292536/found-solution-to-the-0x80888002-error-code-on-attempting-to-install-22h2-upgrade-on-windows (learn.microsoft.com)