Locate the following key in the registry: HKEY_CURRENT_USER\Software\Microsoft\Windows\DWM
Modify the following value (REG_DWORD): Composition
Change the existing value to 1.
Modify the following value (REG_DWORD): CompositionPolicy
Change the existing value to 2.
Close Registry Editor.
Open an elevated Command Prompt window. To open an elevated Command Prompt, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator. You can also type CMD in the search box of the Start menu, and when you see the Command Prompt icon click on it to select it, hold CTRL+SHIFT and press ENTER.
In the Command Prompt window, type: net stop uxsms
press Enter.
Wait for the Desktop Window Manager Session Manager service to stop, then type in: net start uxsms
press Enter.
Wait for the Desktop Window Manager Session Manager service to start. You *might* need to restart your computer.