version conflicts

In CPanel, I have three Adobe icons (Adobe AIR- version 3.1.0, Acrobat Reader - v. 10.1.7, and Flash Player, v 11.9.900) In many instances, an emailed pdf download will not open and giving an error msg that Adobe's already running.  I would assume I'd uninstall the oldest version of the three (the Adobe AIR) but want to be sure I don't lose documents or a necessary program before any changes are made.  Please advise!!