2. Click  this button in it  and then the "patch files" button.
 and then the "patch files" button. 
3. Now click this button  and click "patch files".
 and click "patch files". 
4. Reboot.
5. Download new themes from here or somewhere else. 
6. Put the downloaded files into the "C:\Windows\Resources\Themes" folder. 
7. Finally goto Desktop -> right click and select "personalize". Select "Themes" and select your new theme and apply. Done.