License key data resides in different registry branches depending on whether installation was per-machine or per-user. Key locations include Software\Classes\Software\think-cell for standard storage, Policies keys for group overrides, and Office add-in paths. Automating License Key Deployment
Use Task Manager to close POWERPNT.EXE or EXCEL.EXE . think cell license key registry
Ensure write access to registry keys and %APPDATA%\think-cell . License key data resides in different registry branches