Carl -
I upgraded to 4.5.1, Build 18 a long time ago. Go here for some info -
http://digital.ni.com/softlib.nsf/954feaeea92d90918625674b00658b83/22af943a4c9fb25586256ae6006c92be?OpenDocument
But I don't remember if I got the download from the NI site or if one of the support people sent it to me. If you contact NI they can help you. Or they'll respond to this thread.
Upgrade was seamless for us.
Aaron Gesicki
Sparta, WI