I purchased Elements 10 as a gift for someone with a MacBook Air which doesn't have a cd drive. Can an external drive be used to install the program from the cd or is there an altenative?
Try downloading it, install it and use the registration code from your purchased version to activate it.
Copy the disc contents from the external drive onto the hard drive of the MBA, and run the installation that way.
Try an keep this disc safe with you for any future use.