It would really be nice to get an answer here.
Because Reader4PC isn't working anymore(login doesn't work) although I could login into Adobe ID with the same credentials.
So I need to use Adobe Digital Editions 4.5. But when starting the Software nothing happens. I already deinstalled it and it didn't help.
Please help us here.
I did contact the Adobe Support. They gave me the following solution / workaround.
Go to the Adobe Digital Editions and click there with the right mouse. Then choose "run as administrator".
With this the ADE is starting up now :-)