"TechWeb has posted an article regarding Vista's new license and how it allows you to only move it to another device once. How will this work for people who build their PCs? I have no intention of purchasing a new license every time I swap out motherboards. 'The first user of the software may reassign the license to another device one time.
If you reassign the license, that other device becomes the "licensed device," reads the license for Windows Vista Home Basic, Home Premium, Ultimate, and Business. In other words, once a retail copy of Vista is installed on a PC, it can be moved to another system only once. ...
Elsewhere in the license, Microsoft forbids users from installing Vista Home Basic and Vista Home Premium in a virtual machine. "You may not use the software installed on the licensed device within a virtual (or otherwise emulated) hardware system," the legal language reads. Vista Ultimate and Vista Business, however, can be installed within a VM.'" Overly Critical Guy points out more information about changes to Vista's EULA and the new usage restrictions. "For instance, Home Basic users can't copy ISOs to their hard drives, can't run in a virtualized environment, and can only share files and printers to a maximum of 5 network devices."