If you're in a rush and want to play tonight while Martin is probably sleeping... I think you need to fire up the hauptwerk installer and just set the paths to your d drive? There are few folders in the HW installer that you can choose, they are all set to c, but when you "reinstall" and choose D for all your folders (think there is 4 of them or so) then you should be good.
I think anyway... this comment not subject to warranty or "fitness of use!"