This link will help to replace the HWID file easily in single click
https://www-secure.symantec.com/connect/downloads/remotely-run-symantec-antivirus-related-batch-file
After that required to restart the client system.
It's working finely. So try this one.
For the future
if you are using the image disk for the OS deployment. Try to create the disk with Sep service stop
Also remove the below files
Hkey_local_machine\Software\Symantec\Symantec Endpoint Protection\SMC\SYLINK\Sylink\(HardwareID)
C:\Program Files\Common Files\Symantec Shared\HWID (sephwid.xml)
This link help you to create the OS IMAGE Disk
http://www.symantec.com/business/support/index?page=content&id=TECH102815