Central Trial - Ad hoc support

Hi,

I'm on a central trial and from what I can tell there is supposed to be an ad hoc support option available under the computers list but it's not there. Does anyone know if this just isn't included in central or if it only appears after purchase etc? From youtube videos it should be there and I can't see it moved anywhere? Trial runs out in a few days and if we can't do ad hoc too then we'll have to do something else I think.