The end-user license agreements governing both the Home Basic and Home Premium editions of the OS specifically forbid users from booting the software "within a virtual (or otherwise emulated) hardware system." The blanket prohibitions don't apply to the higher-end editions of Windows Vista.
That means Linux aficionados or users of Apple Macs will not legally be able to use software from vendors such as Parallels or EMC's VMWare to create so-called virtual machines on their desktops to run Vista alongside their favorite OS. Windows users wanting to run Vista in a virtual machine environment for security or productivity purposes also will need either the Business or Ultimate Edition.
In his blog, Parallels head of marketing Ben Rudolph says the licensing policy could cost Microsoft some new customers. "This strategy could hold back users who embrace cutting-edge technologies like virtualization, which means they won't upgrade to Vista. This means that Microsoft has effectively lost an upgrade customer [in the case of Windows PCs] or an entirely new customer [for Mac and Linux users]," Rudolph writes.
Even users who shell out for the more expensive Ultimate or Business editions of Vista aren't free to use the software in virtual environments any way they want. "If you do so, you may not play or access content or use applications protected by any Microsoft digital, information, or enterprise rights management technology or other Microsoft rights management services or use BitLocker," states the license agreement for Vista Ultimate and Vista Business.
BitLocker is a data encryption feature that's integrated into the Vista operating system.