Microsoft to let users downgrade from Windows 7 to Vista or XP
It looks like Microsoft plans to continue allowing downgrade rights once Windows 7 is released. Not only will users be able to downgrade to Windows Vista, but they'll be able to skip an entire generation of operating system and downgrade to Windows XP.
Windows 7 isn't the resource hog that Windows Vista is. So it's not likely that Microsoft will be offering these downgrade rights to netbook users. But corporate customers who aren't ready to upgrade hundreds of computers at once might prefer to buy new computers running XP than Windows 7. It's likely that you'll need to purchase a computer with a Windows 7 Enterprise or Ultimate license to qualify for the downgrade.
Microsoft isn't commenting on the deadline for downgrading to Windows XP. But an early report indicated that the downgrade option would be available through April 30, 2010.