retail keys using: cscript ospp.vbs /unpkey: Step 3: Use a Trusted Conversion Script
“Or,” Gerald said, “you can run the real nuke. Not Microsoft’s scrubber. Use the c2rintuninstallstring from the original Retail setup.exe. Extract it from the ISO. Run it with /uninstall /force /s /quiet /removereallyreallywell — but that flag doesn’t exist. You have to manually delete the %ProgramData%\Microsoft\Office\ClickToRun folder while the uninstaller is paused in mid-cycle, then kill the OfficeClickToRun service process tree. It’s a race condition.” retail keys using: cscript ospp