For UAC:
In the Group Policy Editor, browse to Computer OR User Configuration > Policies > Windows Settings > Security Settings > Local Policies > Security Options. At the very bottom you'll find all the UAC group policy setting options.
Changing UAC requires the client to be rebooted for the new policy to take effect.
For Network Discovery:
In the Group Policy Editor, browse to Computer OR User Configuration > Policies > Administrative Templates > Network > Link-Layer Topology Discovery. Turn on Responder (RSPNDR) driver = Enabled, select your profile options (Domain).