This step only needs to be done once and only on PCs.
Once the OverDrive Media Console has been installed >> Open the software >> Tools menu >> Windows Media Player Security Upgrade.
Without this upgrade the WMA audiobook will not be able to be downloaded to your computer. You will get an error message about not having the rights to download the title.
If the "play" button does not light up (become "clickable") after multiple tries, follow these instructions for a manual upgrade.