In order to properly uninstall USS follow the steps bellow:
1. Use the uninstalling feature in the control panel for USS.
2. Delete the database components (Default database name is USS_MDB and user ussmdbadmin). Backup the database if needed before deleting it.
3. Use the database cleanup utility to remove the USS product from the MDB database.
The database cleanup utility can be found in the Service Desk Management installation media files under the folder <DVD SDM>\DBCleanupUtility\DBCleanupUtility.bat
Instructions of how to use it can be found in the link bellow:
Run the database cleanup utility
4. Modify the file.com.zerog.registry.xml under the directory C:\Program Files\Zero G registry after Unified Self-Service is uninstalled.
Zero G Registry can be a hidden folder, so you have to enable the Show Hidden Folder option on Windows. Remove the following node <product name="Unified Self-Service"> and two other components nodes that are related to Unified Self-Service:
5. Restart the server.