0 Pre-requisites
before you start, it is recommended to restart the Windows 7 themes – this may already fix your problems
1 Scan For Corrupt System Files
Whenever you run into serious problems, it is recommend to do a system file check
1. StepOpen an elevated command prompt
2. StepEnter sfc.exe /scannow and hit Enter
2 Have You Used Windows 7 Aero Themes Before?
If you know that your PC is capable of running them, then proceed, else you should make sure that your graphic card / mainboard actually supports the themes service – for that WDDM driver (Windows Display Driver Model) support is required
3 Reset Privileges
We have a registry tweak that can reset your Themes service values and reset the RequiredPrivileges key that is important for the service to work properly