Script to remove Hardware Id.If you are comfortable to proceed with script then try this on a test machine and then on all machines.

Create a batch file and insert he following lines and run it from GPO.

start smc -stop
Del "%programfiles%\Common Files\Symantec Shared\HWID\sephwid.xml "
reg import HardwareID.reg
start smc -start

create another batch file .File name should be HardwareID and add the following lines and deploy it from GPO.

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection\SMC\SYLINK\SyLink]
HardwareID=""

 once done all the machines need to be rebooted for creating the new HWID.