Finally! After years of confusing consumers with multiple, slightly different versions of the same operating system, Microsoft announced today that Windows 8 will come in only four versions: One for home use, one for business, one for devices running ARM chips, and one for large enterprises who buy in bulk.



The version called simply "Windows 8" is designed for home users. "Windows 8 Pro" is for business users and includes features for encrypting a file system, virtualization, and domain management.

"Windows RT" is the new name for what had been called Windows on ARM. You won't be able to purchase it on its own; It'll come preinstalled on PCs and tablets that run ARM processors. Windows RT won't be able to run traditional X86/64 desktop software. Instead, it'll run touch-oriented apps based on Windows Runtime (or WinRT), Microsoft's programming model for mobile apps. Apps for the touch-oriented Metro interface are built using Windows Runtime.

Windows 8: Key Features by Version

Feature nameWindows 8Windows 8 ProWindows RT
Upgrades from Windows 7 Starter, Home Basic, Home Premiumxx 
Upgrades from Windows 7 Professional, Ultimate x 
Start screen, Semantic Zoom, Live Tilesxxx
Windows Storexxx
Apps (Mail, Calendar, People, Messaging, Photos, SkyDrive, Reader, Music, Video)xxx
Microsoft Office (Word, Excel, PowerPoint, OneNote)  x
Internet Explorer 10xxx
Device encryption  x
Connected standbyxxx
Microsoft accountxxx
Desktopxxx
Installation of x86/64 and desktop softwarexx 
Updated Windows Explorerxxx
Windows Defenderxxx
SmartScreenxxx
Windows Updatexxx
Enhanced Task Managerxxx
Switch languages on the fly (Language Packs)xxx
Better multiple monitor supportxxx
Storage Spacesxx 
Windows Media Playerxx 
Exchange ActiveSyncxxx
File historyxxx
ISO / VHD mountxxx
Mobile broadband featuresxxx
Picture passwordxxx
Play Toxxx
Remote Desktop (client)xxx
Reset and refresh your PCxxx
Snapxxx
Touch and Thumb keyboardxxx
Trusted bootxxx
VPN clientxxx
BitLocker and BitLocker To Go x 
Boot from VHD x 
Client Hyper-V x 
Domain Join x 
Encrypting File System x 
Group Policy x 
Remote Desktop (host) x