CNet News has a good analysis of Microsoft’s last minute decision not to expand their license to allow running the lower priced versions of Vista. Microsoft has claimed this is for security reasons since virtualization introduces security risk. Those security risks exist for all Vista versions and in fact for any OS. My favorite part is a quote from Paul DeGroot, an analyst with Directions on Microsoft:
If you want to make your product more secure, then make your product more secure.
when talking about the license agreement (which few read) as being the wrong place to set security policy which is absolutely on the mark.
Because the Microsoft license prevents using some versions of Vista on virtualization software such as Parallels the VM companies cannot provide support for those versions running on their software even though the software will probably install just fine.