does it make any different in which order i install them?i have on my windows machine ppcs5.5 which i would like to keep.
You can install PrPro CS6 on the same system with PrPro CS 5.5 with no conflicts. It doesn't matter which order you install the apps in but if they share the same sorts of primary formats, the default will associate to whatver you install last. In the case of Audition and prPro, there are few, if any, formats that would not keep their initial association because audio-only files will not auto-associate to prPro and video files will not auto-associate to Audition. Besides, it's easy enough to change the association back at the OS level after install if needed.
thanks a lot