The Beta of Windows 7 and Windows Server 2008 R2 have been released for TechNet and MSDN subscribers. It is available from here. For non-MSDN and TechNet subscribers, the beta of Windows 7 will be available on Friday 9 January 2009 from here.

Windows 7 and Windows Server 2008 R2 are based on the same code base, and are derived from Windows Vista and Windows Server 2008. Microsoft has built a lot of functionality into the new releases, building on what foundation work was done in Windows Server 2008 and Windows Vista. If an application runs well on Windows Vista, it will most likely run well on Windows 7.

For me, the improvements in Windows 7 are:

• Considerable performance improvements in terms of boot, wake from sleep and user interface responsiveness. In some cases, the difference is dramatic. Even on older hardware and the new WebBooks, performance is really impressive. Installation is blazingly fast.
• It is already extremely stable and I use it on my primary machines already.
• Configurable User Access Control (UAC), leading to less pop-ups for when elevated rights are needed by an application
• Simplified, yet very clever improvements, to the Task Bar and the Notification Tray areas
• Internet Explorer 8
• Bitlocker can protect removable storage also
• Consistent Search from a user interface perspective, and you don’t even notice it when it is busy indexing your data. Searching e-mails, files and SharePoint is performed in one place
• The concept of libraries of documents. Not everything has to be in My Documents to be shown in the Documents view

Please ensure that you download the beta from one of the Microsoft web sites and not from a 3rd party or peer-to-peer network. You know what you get from Microsoft, from other sources, you may have some extra non-Microsoft code included. The beta Expires 1 August 2009.

For more information, see the Windows Product Group Blog