I have had a very frustrating experience trying to install a new version of DM. I had a fully functional 4.3 running fine and tried to "upgrade" to 4.6. I experienced the four "dll failed to register" errors like many others have. I was able to get beyond that problem with posts from the forums. Then I could never sync because DM could not accept that I had an internet connection and so could not configure. I tried every trick I could find in the forums including clean installs many times. I eventually ended up back at DM 4.2sp2 and all is working fine.
I was never able to discover the cause of these problems but they seem to be common. Is there a program similar perhaps to Crackmem that will help with an installation of DM? If a conflict is found (dll or otherwise) it could be resolved or at least pointed out so the user can fix it.