i need help for the installation of digital editions

My problem with digital editions 4.0.3 is that i can´t open the program. I install the program several times but it doesn´t open. So  i have made a new acces with adminrights where i tried it, but this dosn´t works. I have install version 3.0 and 2.0 but there i became a error message on both accounts that the progran no longer works. I hope that someone can help me i need the program for my ebooks. As information i have an pc with windows 7.