How to enable Sylink debugging for the Symantec Endpoint Protection 11.x and 12.1 client in the Windows Registry
http://www.symantec.com/business/support/index?page=content&id=TECH104758
Symantec Endpoint Protection Client installation failed: error “"Pending system changes that require a reboot have been detected" "
http://www.symantec.com/business/support/index?page=content&id=TECH208775
Symantec Endpoint Protection 12.1: Best Practices for Disaster Recovery with the Symantec Endpoint Protection Manager
http://www.symantec.com/business/support/index?page=content&id=TECH160736