Error:Unable to activate screen-copy protection

One of our customers cannot install the protected ebook, as it gives an error: Unable to activate screen copy protection.
How to solve this problem?
Thank You.

Hi @Man101,

Your client is most likely using Windows 7. Ask them to activate “Windows Aero Themes”.

How do do that? And Why should the theme matter?

There is a requirement for the content protection feature you use in your ebook.
Review the help here:

Desktop Window Manager and desktop composition must be enabled:
How to do it: