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 CC has been activated twice in June & september of this year, so when you install it on the second computer or for the third time & when you to activate since it has been activated already twice, there will be an option of deactivating it from the previous computers, please click on that. OR you can deactivate it from your firs computer & then follow the below procedure.Activation & Deactivation Help
Next it will allow you to activate on your new machine,
Now you can go back to your first computer, log out & log back in of Desktopp CC App, launch any product, if there is any product to buy, in that prompt there will be an option to " license the software", please click on that & sign in.
It will reactivate the CC on the first machine.
You have already deactivated it from one machine, hence you can activate it on third computer.