Cloud License allows 2 activations http://www.adobe.com/legal/licenses-terms.html
-Install on a 2nd computer http://forums.adobe.com/thread/1452292?tstart=0
-Windows or Mac does not matter... 2 on the same operating system, or 1 on each
Remove license on a computer http://forums.adobe.com/thread/1442423?tstart=0 may help
-http://helpx.adobe.com/x-productkb/policy-pricing/error-maxium-acitvation-exceeded.html