ADE not opening with either 4.58 or 3.0

I've seen other threads on this topic.  I tried renaming the My Digital Editions folder, and that didn't work.  I've been using 3.0 for about three months because version 4.5 stopped opening.  I was using it 5-6 days per week, and all of a sudden it stopped opening yesterday.  I've tried the suggestions mentioned in previous threads, and none of them have worked.  What am I missing?