I cannot find any way to authorize my computer

I have Adobe Digital Editions 4.5.  I am trying to use it with some Google Books purchases of mine.  When I first tried to authorize my computer, I used my Adobe ID.  After submitting, I’m told that Adobe IDs no longer work for authorization and I have to deal with ByteBooks somehow.  There is a long link for a help page at Adobe, but the text cannot be copied.  When I type it in, however, I am told that the page does not exist.  I went to ByteBooks and I created an ID.  I went back to Adobe Digital Editions and it told me the ID was invalid.  There is no option to select ByteBooks as a vendor in ADE so I typed in my ByteBooks ID while keeping Adobe as the vendor. I tried to contact ByteBooks but both their email and forum links do not work.  What is the secret to authorizing my computer for use with Adobe Digital Editions?  Thanks.