While there aren’t many third-party themes available for Windows 8 yet, they are coming – it’s a trickle right now but their numbers will continue to build as Windows 8 become more mainstream. So, you want to try them out, don’t you? Not so fast. As with previous editions of Windows, Microsoft doesn’t allow users to install third-party visual styles, or in other words, unsigned themes on Windows 8. And just like with previous editions of Windows, the restriction is easy to override. One simply needs to edit or patch a few files - in Windows 8’s case, those files are themeui.dll, Uxlnit.dll and uxtheme.dll.
Pre-patched files are already available on the Internet. They just need to be downloaded and swapped with the original. Don’t worry, you don’t have to do that manually. Theme files patching tools are available for that. Here are some that you can use.
Note: Create a system restore point before using any of these tools.
UltraUXThemePatcher is the best one available at this moment. This all in one theme patcher supports not only Windows 8 but Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, and Windows 7 as well. Both 32bit and 64bit version are supported.
If for reasons unknown, UltraUXThemePatcher doesn’t work, you can try UxStyle for Windows 8 but only and only if you are using the 64-bit edition. UxStyle was coded by Rafael Rivera of WithinWindows.com.
To use these tools you simply have to run it and click on the appropriate button on the program, and the rest is magic. Restart your computer to make sure everything is in the right place. Now you are free to install custom themes.
Copy the custom visual style files to C:\Windows\Resources\Themes. Then right click on the desktop, select Personalize and you should see your new theme listed there.