oh wait, so why is yours in a separate folder and not in a self contained package? That's how mine came in. Maybe I should look to a reinstall, can you provide me with the link you downloaded with?
When I download the .dmg file, this is what I get:
also in the readme.txt it says this:
"To install, copy REAPER.app and (optionally ReaMote.app if you would like to
be able to use this computer as a ReaMote slave) to your Applications folder."
so there is no installer that would even make a separate folder like that