SEP client installation routines check for the existence of the following software
and blocks migration if this software is detected:
■ Symantec AntiVirus client and server 8.x and earlier
■ Symantec Client Security client and server 1.x
■ Symantec Client Firewall 5.0
■ Symantec System Center, all versions
■ Symantec Reporting Server 10.x
■ Confidence Online Heavy by Whole Security, all versions
■ Norton AntiVirus and Norton Internet Security, all versions
You must uninstall this
So you need to Un-install Symantec Client Firewall