Assuming you're using Ubuntu or similar, the easiest way to install ADE 1.7 is via Winetricks. Which you can find in the software centre or by clicking here.
Winetricks is launched via the terminal.
1. Open the terminal and enter $ winetricks
2. Select and OK the "Install an App" option.
3. In the next screen you select and OK the "Adobe Digital Editions" option.
Hope this helps.