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If you have a powerful PC, Longhorn will provide the high-end Aero Glass user interface, which includes stunning animations, vector graphics-based icons and screen elements, and translucencies. Less powerful PCs will utilize the Aero Express user interface, which provides an Aero Glass-like UI that is based on XP-level graphics technologies. For legacy systems or those used by corporations that don't wish to retrain users on the new Longhorn UI, Longhorn will also offer a backwards compatibility mode that resembles the stock Windows 2000 user interface.
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