Windows 7 has been developed in six versions, of which Windows 7 Home Premium and Windows 7 Professional are the most widely used.
Windows 7 Home Premium is designed for desktop and laptop computers at home and includes Windows Media Center, Windows Aero and touchscreen support.
Windows 7 Professional is designed for both private use, enthusiasts and small businesses. Windows 7 Home Premium Professional has the same interface and includes all features found in Windows 7 Home Premium. With Windows 7 Professional, it is possible to participate in Windows Server domains and it is also possible to encrypt all content on the hard drive.
Windows 7 Ultimate is intended for enthusiasts and includes all features of Windows 7 Enterprise, but with the crucial difference that Ultimate can be purchased in stores and at retailers.