Second try at: How to get a completely clean/pristine installation of nm on Ubuntu 12.10?

[Chris Green <cl isbd net>]

Sorry about that last message with this subject, the message had a
perfectly sensible question in it but it had very little relation to the
subject line! 

So, to the question as in this message's subject.

Given that I have several systems where I have massaged various files in
/etc/network and /etc/NetworkManager by hand how can I get them back to
a state where all of the network configuration is managed by Network
Manager?  I have tried uninstalling and reinstalling network-manager but
that doesn't seem to do it.

-- 
Chris Green