You can add multiple devices to your ADE account. Having two or more devices registered to the same account is useful if you want to read your book on multiple devices without having to buy it again. However, if you’ve activated too many devices, or if you want to update your OS, or simply need to move to a new or upgraded PC, you may want to deactivate ADE so you can free up your books for more devices or to put them back on the same PC after you upgrade it. You can deactivate ADE directly from the application. Here’s how to do it.
Select the menu item Help–> Erase Authorization.
While deactivating in ADE 4.0.3, the user has to provide valid user credentials to deactivate.
For Vendor account, the user has to provide both the User name and Password by selecting the vendor.
For Multiple or Joint Accounts, each accounts needs to be deactivated separately.