Windows 7 offering Aero Glass, advanced windows navigation features like Aero Snap and Aero Peek, and multi-touch, as well as the ability to both create and participate in Home Groups.

Windows 7 Pro builds on Home Premium and adds features like Domain join, Remote Desktop host, location aware printing, EFS, Mobility Center, Presentation Mode and Offline Folders.

WAU for users with geniune Windows 7 software already on their PC and they want a higher edition. Windows 7 Home Premium to Windows 7 Pro. For preinstalled windows or notebooks and desktops. Must be the same bit os. ie 32bit to 32bit or 64bit to 64bit.