How did you purchase Land Desktop? Through a reseller? Or on E-Bay?
I think I've kind of blocked a lot of Land Desktop stuff from memory, but it seems like Autodesk rolled the old Civil Design and Survey modules into Land Desktop Companion, which you could only get by getting a license of Civil 3D. They still had a Land Desktop, but it was Land Desktop without the Civil Design or Survey modules. If you wanted the full functionality of Land Desktop Companion, you had to buy Civil 3D. At least, that's the way I remember it.
So I suspect you got the old Land Desktop, and not Civil 3D with Land Desktop Companion. If this is the case, you don't have the Civil Design module, and I don't know of any way you can "simply load it"... If you got this from a reseller, check with the reseller.
-- Sinc
http://www.ejsurveying.com
http://www.quuxsoft.com
Sinc