Follow these steps
1)Run ->Cmd
2)Type netsh
3)Firewall
4)Now type in "set opmode enable" to start firewall and "set opmode disable" to stop fire wall.

By corrupting, or deleting data

usually you should have one per site if that is not possible you would want it centered in your network

to create an OU in active directory users and computers you would right click your domain and select new then OU name it what you want....to create or assign a GPO to said OU you can right click the OU and selct properties then select the group policy tab you will then have many option (add, new)

Policy is collection of users settings and configuration.Through policy you can deny and permit user for specific settings.




Ou is collection of objects its behave like folder through which you can manage objects and provide policy.