This is a tip for students who are lucky enough to study at places that have Microsoft Academic Alliance set up. These students have access to free copies of Windows 7 which may well be better than the ones on their machine.
If you fancy upgrading your Windows 7 machine (which may have the Home version of the software) to the more advanced version provided by MSDN AA you don’t have to re-install your operating system. You can use the Windows Anytime Upgrade command to enter the product key for your new version and the upgrade happens for you automatically. You can find out more about this here.