Hi,
 
I just posted asking for help, but figured it out.
 
If you have a drive/partition/other computer where Rapture was successfully installed (i.e. a 10.6.8 or lower system) and you need to install Rapture on your 10.7+ system, then copy
 
/Applications/Cakewalk/Rapture
/Library/Audio/Plug-Ins/Components/Rapture.component (the AudioUnit Version)
/Library/Audio/Plug-Ins/VST/Rapture.vst (VST version, I assume, I only ever installed the AU version)
wherever the RTAS version is installed (don't use RTAS, so I don't install this version either)
/Library/Audio/Plug-Ins/Rapture Content
/Library/Preferences/com.cakewalk.Rapture.plist
/Library/Preferences/com.cakewalk.rp.plist
 
from the old harddive to the new one. The PList files were the key to getting everything to work right.
 
Worked for me.
 
Good luck,
 
Brian

Chad - Another one needing that solution please. Bought and paid for the software (advertised as for 10.6 and up), but can't install it due to serial number issue.

Hi everyone! Is that workaround still available? I considered Rapture to be a lost case on Mac, but I heard some people made it work and it seems that I found those people :). Would anyone be kind enough to send me the instructions? I would really appreciate it!!! Thanks so much to all of you.