The tool modifies the uxtheme.dll file in Windows 7, Windows 8, or Windows 8.1 to load any theme you like-by default, it checks themes you attempt to load and only loads them if they're signed by Microsoft. Download the UltraUXThemePatcher installer, run it, and reboot your computer to patch your system. However, Microsoft doesn't support third-party Windows 7 dark themes. They're designed for accessibility, not eye candy. They also don't use Aero, so they're not properly hardware accelerated and don't look as nice. Dark Themes for Windows 7 and Windows 8.1
