Hello,
I agree with Mick above.
Secondly, what version of SEP are you carrying? Is that SEP 12.1 RTM => 12.1.671.4971
SEP 12.1 RU1 => 12.1.1000.157?
Not forgetting you are carrying Windows 7 machines. So, please check the UAC settings on the machine. Could you turn off the UAC on the Windows 7 machine?
Again, we would like to also know if you are carrying any Proxy on this machine?
Check the Step 3,4,5 and 6 from the Article below:
https://www-secure.symantec.com/connect/articles/how-configure-proxy-settings-symantec-endpoint-protection-manager-sepm-121
Hope that helps!!