Windows 7 is the Microsoft Windows operating system released commercially in October 2009. In development, Windows 7 was known by the code names "Blackcomb" and "Vienna."
Windows 7 is built on the Vista kernel. To many end users the biggest changes between Vista and Windows 7 are faster boot times, new user interfaces and the addition of Internet Explorer 8. The OS is widely available in three retail editions: Windows 7 Home Premium, Professional and Ultimate. Starter, OEM and Enterprise editions are available in some markets.
Windows 7 features:
DirectAccess for Mobile Workers - Allows IT administrators to update Group Policy settings and distribute software updates any time the mobile device has Internet connectivity, whether or not the user is logged on. DA supports multi-factor authentication and encryption.
XP mode - Allows older applications designed for Windows XP to use a virtualized version of the XP operating system. To the end user, the applications seem to be running right on the Windows 7 desktop.
BranchCache - WAN optimization through more effective use of local, read-only caches.
BitLocker To Go - Extends on-disk encryption and key management techniques to portable storage devices.
Virtual hard disk support - Allows you to mount a virtual hard disk (VHD) and interact with it as if it were a physical drive.
Enterprise Search - Extends search to remote document repositories, SharePoint sites and Web applications.
AppLocker - Allows IT administrators to use Group Policy to specify rules about what software applications can be run on a particular user's desktop.
Enhanced VDI - Allows administrators to use the same master image for both remote clients using virtual desktop infrastructure and traditional desktop computers.
According to Microsoft, Windows 7 requires 1 GHz processor (32- or 64-bit), 1 GB of RAM (32-bit) / 2 GB of RAM (64-bit), 16 GB of available disk space (32-bit) / 20 GB of available disk space (64-bit) and a DirectX 9 graphics device with WDDM 1.0 or higher driver.
Paul Thurrott's Supersite for Windows offers news, reviews and advice about Windows 7.
Wikipedia has compiled a comprehensive list of every new Windows 7 feature.
Microsoft provides the lastest news about Windows 7.