Can you help? Converting from PC to Mac for Design Standard CS6

Hello,

I have recently purchased a macbook pro and downloaded the files for Design Standard CS6, I install the application and then enter my product key which works however it says
"this product is valid but we could not find a qualifying product on this computer"

It then tells me that if I want to use the code I must have one of the following products and the serial code, then it gives me a list of products none of which I want such as Design Standard 5, Web Premium etc

I didn't need any of these on my PC I just downloaded the application and used my code

Can anyone offer any advice here?

Thanks

S