If you're the kind of user who likes to change the system's visual theme quite often, here's UXTheme Multi-Patcher - a little app that's going to make things much easier for you.
With UXTheme Multi-Patcher you replace a specific system DLL with a tweaked version of the same file, thus enabling Windows to support third-party visual themes. In this way, you'll have a much wider choice of themes when customizing your system.
UXTheme Multi-Patcher is dead simple to use: run the EXE file and the correspondent DLL library will be patched. Bear in mind that you'll get a message warning you about a system element about to be replaced; you'll need to cancel that warning if you want the patcher to do its job.
After patching the DLL file, simply restart Windows and you'll be ready to begin using third-party themes. Also, if at some point you want to go back to the original DLL file, simply run the UXTheme Multi-Patcher again.
UXTheme Multi-Patcher tweaks a specific DLL file on Windows so that you can use third-party visual themes.