select the ones you want to turn on and click on the bulb. But I see you're just allergic to driving. :
I'll put it online so maybe take a look at it. http://www.it.rhino3d.com/4/help/rhinov4.htm
hi enri, you have actually posted the question before you consult the guide.
However I meant a command that ignites a layer group all together without having to select them every time (they are about 7-8 layers in a pile up of 50 layers and having to do the operation by hand is boring).
as I said above management status levels ho risolto.