Im having the same problem. Iv tried:
program files/cakewalk/sonar platinum
And
Program files(86)/cakewalk/sonar platinum
And both come up with a message saying "This folder does not appear to be sonar installation folder because it does not contain the sonar application and ressources files, please select corect folder"
I had a look in the program files/cakewalk/sonar platinum. Folder and the install application is there so i dont understand why it wouldnt work...
Any suggestions of a different path or way around this?