Then what you need is WindowBlinds. There is a 30 day free trial and a paid version available. Both will change your start menu, windowframes, taskbar and more. There are hundreds, maybe thousands of skins to choose from so I'm sure you'll find something you like.
And don't worry, WindowBlinds doesn't hack any system files and be easily uninstalled if needed (but why?) Give it a try and if you like the trial, you may want to look at Object Desktop which has WindowBlinds and lots more to really dress up your desktop. It's much cheaper than buying the apps one at a time.
You will need to install Impulse to install and update the paid versions, but don't worry about that either. It doesn't have to be running to use any SD software, only when you want to check for updates, archive or re-install your programs. This is a real plus if you have several programs to keep track of.
Happy Downloading.