Check the connectivity to the management server.
Type the following command In the browser command line
http://management_server_address:8014/secars/secars.dll?hello,secars
If it working then simple question.
Have you install the OS threw image disk??
If it then pls delete the hwid file from below path
Hkey_local_machine\Software\Symantec\Symantec Endpoint Protection\SMC\SYLINK\Sylink\(HardwareID)
C:\Program Files\Common Files\Symantec Shared\HWID