Windows X's Live recommends:
Before and after making any changes to your system or installing any software including Seven Transformation Pack, we strongly recommend you check Windows for registry errors.

Microsoft is in no hurry to deliver the first service pack for Windows 7. It must be said that while the Windows Vista SP1 was expected as the messiah to solve many problems of compatibility and improve some performance, SP1 Windows 7 will not have to deal with such problems. 
Thus, although a beta version of Windows 7 that SP1 and Server 2008 R2 is available, the final version should make its appearance during the first half of 2011. Once again, Microsoft has thought of playing again for considering a deployment of its operating system, waiting for SP1 is not necessary. 

For Windows 7, Microsoft still evokes some specific changes with this SP1. Improving connections between computers and Windows 7 HDMI audio materials, correcting a problem for printing via the XPS document viewer with several differently oriented pages (portrait and landscape). Support has been added to improve customers for the Windows 7 platform interoperability and the ability to communicate authentication information between organizations. 

For Windows Server 2008 R2, two new features are introduced Dynamic Memory Microsoft to allow Windows Server Hyper-V to dynamically allocate more or less memory to each virtual machine, and the Platform for FX graphics acceleration to allow remote users remote to work in an environment rich (Windows Aero, multimedia, 3D applications). 

The beta of SP1 for Windows 7 and Windows Server 2008 R2 is available for download in several languages from this page and after filling out a form. This beta is not for individuals.