[dreams]

Glad you were able to get your books on by using the other computer.

I'm still at a loss about that error 0...

Does anyone have an idea or thought about what that error is??

Just another thought with a couple of questions. How many Readers and computers do you have authorized to your account? Do you only have one account? I wonder if maybe your first computer was deauthorized?
From Sony FAQ's

You are allowed to authorize up to six computers (via Reader Library) and up to six portable devices (via USB and/or wireless).

To see what devices you currently have registered to your account;

1.
Launch the Reader Library Software.
2.
Go to eBooks Store and login with your Username and Password.
3.
Click on My account.
4.
Page down to the section "My Authorized Devices" which will show you how many and what devices are authorized to your account.

I found some information you may be interested in on the Adobe page... http://www.adobe.com/products/digitaleditions/help/#getting_started

and something I found farther down the page ...
To transfer a library item to another authorized computer:

1. On the computer you're transferring from, locate and open the My Digital Editions folder, located inside the My Documents folder.
2. Choose the EPUB or PDF files that correspond to the eBook titles you want to transfer.
3. Copy the selected files to portable media such as a flash drive, or e-mail the files to the target computer.
4. On the target computer, copy the EPUB or PDF files into the My Documents\My Digital Editions folder.
5. Open Adobe Digital Editions on the target computer. Choose Library > Add Item, and then navigate to the My Digital Editions folder and select the new files to bring them into the library.

and the other Adobe page information..
http://ebooks.custhelp.com/app/answers/detail/a_id/145/kw/associate%20with%20EPUB%20files/r_id/166

How can I tell if my PC is already authorized?

In Reader Library, please go to the Help menu and click "About". Here you will see information about your Adobe activation status and your Adobe ID.

I figure it's worth a try to check information. I end up learning myself. At least you can get your books on to the Reader, although I know you would like to use the other computer.