InformationWeek: Microsoft has revealed for the first time that Windows 8 will come in four different versions: Windows 8, Windows 8 Pro and Windows 8 Enterprise will run on traditional desktops and laptops, while Windows 8 RT will run on ARM-based tablets. "For many consumers, Windows 8 will be the right choice," blogged Microsoft's Brandon LeBlanc. "Windows 8 Pro is designed to help tech enthusiasts and business/technical professionals obtain a broader set of Windows 8 technologies. It includes all the features in Windows 8 plus features for encryption, virtualization, PC management and domain connectivity." Windows 8 Enterprise "includes all the features of Windows 8 Pro plus features for IT organizations that enable PC management and deployment, advanced security, virtualization, new mobility scenarios, and much more," he added.
Microsoft's last version of Windows--Windows 7--came in six different versions.