I was having the same problem so I contacted support because I have another LogMeIn product and together we found a solution.
It seems that if you had an older version of Hamachi and you installed the Hamachi2, there will some old service files that need to be cleaned up first.
To remove the Service files without reinstalling Hamachi do the following...
Open Hamachi, click System / Preferences / Settings /Advanced Settings -
Scroll down to Service Configuration - select it and click Open - you will come back to this.
Then Open up Services and STOP LogMeIn Hamachi 2.0 Tunneling Engine.
Then go back to the Windows Explorer for the Services and go up one folder level.
Delete the "LogMeIn Hamachi folder" - close Windows Explorer.
START the service for LogMeIn Hamachi 2.0 Tunneling Engine - close the services window.
Open Hamachi and Turn it on and it should be ready for a new network setup!
Enjoy!
BTW Great product!!!