Hi Katy,
Extremely sorry for the crash you are seeing. Which OS you are working on ? Please share the crash logs as well.
+ Please maintain the back up of your preferences and then clean preferences from below location and then try working on Dreamweaver.
On win : C:\Users\username\AppData\Roaming\Adobe\Dreamweaver CC 2014
On mac : ~/Library/Application Support/Adobe/Dreamweaver CC 2014/
The two apps you are seeing are two different version of Dreamweaver. If DW CC was already installed on your machine, it will stay there even after installing DW CC 2014.