Hi Bill,

The new beta versions will install in their own separate directory, so the last beta is in a directory named MoI 3.0 beta Oct-18-2011, the latest beta will install into a separate directory named MoI 3.0 beta Oct-25-2011 so you don't have to uninstall the previous version and the new version won't over write it, it's up to you what you want to do with the older version, of course it'll eventually expire.

Cheers
~Danny~