the Beta version is a completely separate program, so,.. It should be installed into a separate program folder,.
The beta does not need any other version of carrara to be installed,. and it’s not an upgrade to Carrara 8.1
Carrara 8.1 and the Beta should not be installed into the same folder.
The beta version is not supplied with any (carrara native content) but,.. it should show any existing Poser or Daz Studio (content or Runtime) folders.
Try uninstalling the beta,. and if needed Carrara 8.1,. then re-install into separate folders,
Hope it helps