As far as license management goes, you can deactivate the license yourself on a given machine by choosing Help - Deactivate... If the machine is no longer available, you can call Adobe customer support, explain your situation, and they'll help you reconcile their online database to match the systems you actually have in use.
Regarding your "can't see the images" issue... C.Pfaffenbichler is right, more information would be helpful. Don't assume you have to uninstall/reinstall just yet. You may have something basic, like a problem with your image file extensions or a cache that needs clearing.
-Noel