The installer should find the Session Drummer Content path in your registry and show that... usually it's
C:\Program Files\Cakewalk\Vstplugins\Session Drummer 3
If the installer finds an x86 Program folder it will also give you the option of installing to:
C:\Program Files (x86)\Cakewalk\Vstplugins\Session Drummer 3
or both...
I just checked the installer and it says the correct product in the installer....
What's the path to your content on your system?
Cheers,
Rail