Adobe Digital Editions crashes while opening

I've been using ADE for quite some time now but recenty I can't open the program at all. As I click on the icon on my laptop, the main window opens but a few seconds later the program crashes and closes itself. I tried to uninstall it and install earlier versions, but the problem repeats again and again. I'm using the program on Windows Vista and mainly for opening acsm files. I would be grateful for any help, because right now I cannot access any of my books.

Greetings,

Izabella