Hi,
Could you please provide setupapi.log & sisinst.log
Setupapi.logs location: c:\windows\setupapi.log
Teeferinstall.log sourceFolder: C:\Program Files\Symantec\Symantec Endpoint Protection\12.1.1101.401.105\Bin\TeeferXP
Update driver for the Network Interface Card.
Also if possible try these steps:
1) Uninstall SEP client
2) Take back up of the registry
3) Delete the following keys
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog\System\Teefer3
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\eventlog\System\Teefer3
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\services\Teefer3
HKLM\SYSTEM\CurrentControlSet\Services\Teefer3
4) Reboot the machine
5) Reinstall SEP client.