How to FIX: Cannot Change Theme – Aero Themes are Greyed Out. This tutorial contains instructions to fix the following problem in Windows 7: Theme cannot be changed – Themes Greyed Out. Instead of that, all the other settings in the personalization panel are enabled (Desktop Background, Windows Color, Screen Saver, etc.), expect to select a different theme. The following issue has occurred in a Windows 7 based computer: Windows changed to the basic theme and the user cannot change the theme because, when the personalization settings are opened, all of aero themes are greyed out.
