ADOBE ID not working

I have downloaded digital editions 3 and when i enter my ID is says that only ID can be used on a computer.

I am needing help in wondering why it think my ID with email address has been used on another computer.

My computer was wiped and rebooted (ages ago) but its the same computer

I can't/wont be able to transfer my books until ADE is authorized with my ID.

Can any one help.

Thanks