Microsoft Windows Vista Ultimate Upgrade Additional License Pack - 1 PC Lets you run Vista Ultimate Update on one additional computer so you can take advantage of this mobility-focused operating system whether you're working from home, working on the road, or searching for entertainment options Combines all the features of a business-focused operating system, all the efficiency features of a mobility-focused operating system, and all of the digital entertainment features of a consumer-focused operating system Remotely connect to business networks; Windows BitLocker Drive Encryption provides improved levels of protection against theft for your important business data whether you are at home, on the road, or in the office Delivers all of the entertainment features available in Vista Home Premium; includes everything you need to enjoy the latest in digital photography, music, movies, analog TV, or even HDTV 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)