When attempting to upgrade or install the WSS Agent (WSSA), you receive the following error:
The File 'wssad.exe' is not marked for installation
NOTE: the error may be different depending on the WSSA client or UA client
Error for WSS Agent (WSSA):
The File 'wssad.exe' is not marked for installation.
Error for Unified Agent (UA):
The File 'bcua_service.exe' is not marked for installation.
This is caused by registry keys that exist from a previous failed installation or upgrade of the WSS Agent (WSSA) or the Unified Agent (UA).
Run the Microsoft repair tool to repair the corrupt install/uninstall registry keys:
Fix problems that block programs from being installed or removed: