File Locations and upgrading

Hi

I've seen a few examples when installing 9 on PC's where
EndNote 7 had
been installed that the new installation referred to the
file locations
of the earlier installation. (I think that's from Edit +
Preferences +
Folder Locations)

Is this a known issue and are there any recommendations?
What about
installing EndNote 10 when EndNote 9 was already installed?
Is there a
recommendation about uninstalling an earlier version first
and will
user's library files be kept even if they uninstall?

Have a nice day
John Paul