You can install Adobe Digital Editions 4.0 in Windows 7, Windows XP, and Windows Vista by following the steps below:
Click Download tab. Downloads page for Adobe Digital Editions appears.
Click Download Digital Edition 4.0Windows (7.2 MB).
ADE_4.0_Installer.exe file downloads to your computer.
Double-click ADE_4.0_Installer.exe file to start the installation process.
Select the options for the components you would like to install and then click Next.
Confirm the install location and then click Install. Adobe Digital Editions installs on your computer.
After the installation is complete, click Close to launch Adobe Digital Editions.
If you have difficulties with the installation process, see Can’t Install Adobe Digital Editions.