I cannot install Cubase 6.5

When I try to install Cubase 6.5, I get this message: Cubase 6 not found, You need to have Cubase 6 installed.

I do have Cubase 6 installed on my Computer, and it is working fine, so why can it not be detected? :frowning:

Hope anyone can help me with this problem.

t1984k

I have an iMac with OS X Version 10.7.3, processor 2.8 GHz Intel Core i7, 16GB Ram