Setting up response groups will require you to add your PC's hostname to the groups interface. This will allow your Little Green Button to pick up the designated location and response group settings for this device.
If you don't know your hostname, you can find it by right clicking your Little Green Button and choosing the About option.
In the resulting window, click the Technical Info button.
This will open another window, containing all the technical information for your button.
Towards the botton, in the SESSION section, after Host: it will show you your hostname. In the case of the example below, the hostname is CLIENT-033