Vista - Two Versions of Program

I'm using Vista Home and installed Eudora, copied my old Eudora folders from
my old PC (XP) into C:\Program Files\Qualcomm.
If I right click on Eudora, select Properties, set the Privilege Level in
Compatibility to "Run this program as an administrator", I can
see all my copied folders which contain emails sent & received.
If I uncheck the "Run this program as an administrator" none of my copied
data is present and it looks like a fresh install.

The reason I want to fix this is, all the programs that call the email
program (like IE or Windows Photo Gallery, etc) call the
version of Eudora that doesn't have my copied folders.

Or is there a way to have the programs that call the email program, select
the one in C:\Program Files\Qualcomm.

Thanks,

RT