Adobe issue.

Adobe CS3 issue
I have the Adobe CS3 master collection (from my work) and i am having an issue. I want to put this full suite onto an external hard drive and then when i have to restore my Mac i can then get it off of the external.
The problem. I have put it on the external and when i go to put it back on my Mac the software says that is has stopped due to a license issue and then the software closes. I do not know if i should make a copy of the disc so it will always be available to me or is there a way i can make a copy of the software and move it from computer to external and vice-versa.

Either way please help me out and let me know what to do. If the recommendation is to make a copy of the software please let me know how to do that and what software to do it with.

Thank you