[as taken from The Deployment Guys]
The Windows Automated Installation Kit (Windows AIK) is a set of tools and documentation that support the configuration and deployment of Microsoft® Windows® operating systems.. By using Windows AIK, you can automate Windows installations, capture Windows images with ImageX, configure and modify images using Deployment Imaging Servicing and Management (DISM), create Windows PE images, and migrate user profiles and data with the User State Migration Tool (USMT).
GImageX is a third-party graphical version of the ImageX command-line tool from the Windows AIK.
With the release of the Windows 7 beta and also the beta of the Windows Automated Installation Kit I’ve updated GImageX to work with these new beta versions. I’ve also tidied up parts of the documentation around installation and tweaked the “mount” functionality to provide better feedback during the operation.
Please note that GImageX is a third-party tool so please remember that you won’t be able to ring up Microsoft PSS to get support with it! However, it uses the official Microsoft published WIMGAPI SDK which is a supported way of working with WIM files.
Kurt Shintaku's Blog 