Motion sickness....3-4

I Have FCS 2 and motion 3 was installed...I was working on a project, I had all the footage on an external Hard Drive. I gave the External Hard Drive to a buddy to clean up project..he had FCS3 and offered me the upgrade...I said ok..I took it home to install it and realized I didnt have the Necessary Hardware (intel proc) to upgrade..I remember him saying "once I open this footage from FCP 7 it changes it and you wont be able to go back and open with your 6.0.6...

After aborting the upgrade I realize when I try to open my Motion 3 and the templates a window pops up saying "These templates were created by Motion 4" and it crashes..

So I tried to reinstall the motion 3 package and a window pops up, I should mention, I was so frustrated I threw Motion3 icon in the trash..and a new window says

Motion 3 could not be installed on this computer (followed by)Could not find specific message for index 0

Can anyone help me reinstall motion 3 or tell me what I can do to get it back up and running?