When applying customisations, especially to the system files you first need to "patch" three files: themeservice.dll, themeui.dll and uxtheme.dll. If you're getting a taskbar that has a Classic look about it, it's a sure sign these files haven't been patched.
There are many simple theme file patchers about but my personal favourite is Deepxw's
Universal Theme Patcher.
Just run it, it will tell you if files need patching, if they do, when finished, re-boot and you're good to go.