Hello friends.Here is an alternative method, how to enable hidden Windows 7 themes. If previous methods are not working to then apply this method.
At First Go to Control Panel and then click on folder Options.
Note: — If Folder options are not available, change the view to large icons at the top-right corner of the screen.
Now click On the View tab and uncheck the box “Hide protected operating system files (Recommended)”. It will show you a warning; avoid this warning and Click Yes.
Now Go to “C:\Windows\Globalization\MCT\” Inside this folder you will see folders with name MCT-XX where XX will be AU, CA etc. These are the country codes in which these themes are automatically available.
Inside each MCT-XX you will see a Theme folder, now open it and click on the theme file to unlock it. Once unlocked, the theme will be available to you in personalization option.