1. Download the latest version of UxTheme Multi-Patcher and
extract the contents of the downloaded zip file.
2. Next, launch the tool "Run as Administrator", make sure the ‘Set Windows X’s Live as default home page’ option is unchecked (unless you do want your browser’s home page to be changed),
3. click the ‘Patch’ button.
4. You will then need to restart your computer once, and after that, you’ll be able to apply any third-party themes to Windows.
5. Now let’s take a look at some of the best third-party themes available for Windows 8.1.
Abisso 2014 (by ~ezio)