Chances are no one here can help you with this. Changing that particular visual element is not a native feature of Windows 7, it's part of the "modded version". You will want to speak to the creators/distributors of the modded version about this.
And if you downloaded a modded version, I certainly hope you have paid for the standard retail version anyway; if not, it's considered piracy. And I'm going to guess that will not be tolerated on these forums.