Trouble opening books after authorization

Hello there,

It's possible that this question has been asked and answered before, but I wasn't in the mood to scroll through each discussion page. Here is my dilemma:

I installed ADE successfully on my PC. I even managed to authorize my computer (proof: my Adobe ID is the default account, tried different accounts too). However, when I try to open ebooks on my PC, I get a window that says the following:

Authorization Needed

This computer needs to be authorized with a Vendor ID to read book.

I then tried to enter the same Adobe ID I used to authorize my PC and the following message appears:

The vendor account you entered is not associated with the item you are trying to open. Try again.

Please help!