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If you had a boxed version of Adobe, you would need to contact Adobe Support about possibly switching the licensing. For electronic download purchases, especially CS6 upgrades which are ALL electronic, you should already have licenses for Mac and PC in your Adobe Online account, so check there first and see what is available before contacting support.
Regarding Mac, you must have your reasons, but from all the posts I see on the subject, PCs seem to provide more bang for the buck with Premiere and certainly more options for graphics cards for GPU acceleration with the Mercury Engine. Something to consider.
Safe Harbor Computers
If anybody would know if you have a Adobe Masters license (I own both CS5 or CS6) if you can use a PC Adobe Masters cd to install on a Mac? I think Adobe wants to uninstall old version to install on another compute but what about going from PC to Mac? I will keep one of them on a PC and the other on a Mac since I have 2 licenses.
Anyway if anybody knows I can use the same CD and install it on a Mac? I don't know?
Nope If its a windows version you cannot install on a mac.