Microsoft Windows Vista Home Premium Upgrade Additional License Pack - 1 PC Lets you run Vista Home Premium Update on one additional PC, so more people in your household can enjoy its impressive and user-friendly capabilities Features Windows Aero, an efficient and visually stunning interface that makes it easier to accomplish multiple tasks at once by providing a three-dimensional, real-time, animated view of all of your open applications and documents By integrating search throughout the operating system, helps you quickly find and organize large collections of documents, pictures, movies, videos, and music Includes Windows Tablet and Touch Technology that enables you to interact with your Tablet PC-compatible computer with a digital pen or your fingertip instead of having to use a keyboard Upgrade from your current edition of Microsoft Windows XP or Windows 2000 (including Windows XP Professional, Windows XP Home, Windows XP Media Center, Windows XP Tablet PC, Windows XP Professional x64, Windows 2000)