As far as I know the Education version has the same 2 computer provision as the regular version... but since I don't work for Adobe, I am not 100% sure
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
-Both computer Cloud subscriptions may not be in use at the same time
The activation server shows that you have only one activated CC on the Email ID here in forum, so you should able to activate it once again.
Please check this link: http://helpx.adobe.com/x-productkb/policy-pricing/activation-deactivation-products.html
If the issue is not resolved still, you can contact Adobe Support to assist you.