How do I change the authorization on my laptop

I have a windows 7 laptop that was the first place we installed Adobe Digital Edition and we used one email address.  Now we do not have access to the email account any more and want to chagne the authorization account to our new email account.  We have created the new ID on the web and I am logged in using it to write this request for help.  I cannot find any way to change the authorization account on my laptop.  I have tried uninstalling, deleting the digital editions folder, rebooting, and re-installing but it stills shows the authorization account using the old email address.

Ideas?