I'm new to premiere and after I import video files to the program, if I try to play them Premiere crashes. I already tried AVI, WMV, 3GP and others, but everytime I try to play the videos (or even preview them in the workspace), the program crashes. I'm using Premiere Pro CC 7.0.
If you have a CC subscription, you can update to the latest version of Premiere Pro which is currently 8.2. If you have a particular reason to be on 7.x, please update to the latest version of that which is 7.2.3 if memory serves.
Beyond that, try trashing your preferences. which you can do by holding down ctrl+option/alt when launching premiere pro.