UXTheme Patcher allows you to use any 3rd party theme on Windows XP/SP2 (with Themes enabled) by patching the uxtheme.dll (dynamic link library). The process can be reversed but it should be noted that patching the themes service will break Windows File Protection on that single file. If you are prompted to "insert your Windows CD" and you intend to patch Windows to allow 3rd party themes you should click cancel and reboot.