Adobe photoshop 12 organiser closes on opening!

When I open Adobe photoshop 12 organiser the screen opens and goes through opening functions but when it fully opens it then closes before I can open a file. Adobe photoshop 12 does still work for editing when I open Photographs in other locations. There is no indication of what is wrong and why this has suddenly occurred. Please explain and assist in regaining the full Adobe photoshop 12 programme.