Out of the box Windows 7 adds a Shadow around all windows whether active or not. In most cases this enhances the display and makes it easier to focus on the active window. However, in some cases it can be distracting or you just don’t like it and want to remove it.
The first thing you need to do (and probably tried) is to change the Visual Effects under Performance Options like so: go into System Properties and click the Settings… button under Advanced:
Then uncheck the option Show shadows under windows and click OK:
After unchecking the option and closing the window the display immediately changes and all is good. Until you restart Windows. After restarting Windows the shadow most likely returned. If it didn’t then you are probably using Windows with administrative privileges which you should not do!
The problem appears to have surfaced way back in 2009 with Vista. It appears the registry setting to make the change permanent is being applied to the account entered when prompted by UAC. You would think 2 years later this would be fixed.
Then change the option and make the effect permanent you don't even need elevated privileges so, the UAC prompt should not even be called (at least not until you make a change that does require elevated privileges). Fortunately, the fix is quite easy:
- Press Windows Key + R to open the Run dialog
- Copy and paste the text SystemPropertiesPerformance into Run
- Make the change and click OK
Now, when the computer is restarted the effect will remain as set.