Not legally - if you exercised you downgrade rights and installed XP,(either yourself or Dell), then you no longer have a license for win7.
The only way that this would not be the case is if Dell supplied two licences - one for each OS - Check with Dell as they are the only people who can clarify this for you - although it would be very unusual for a downgrade to retain the original licencing in addition to the downgrade OS
When and Why Would Customers Use Downgrade Rights for Windows 7?
Example:
Downgrade rights offer a practical solution. The customer can:
- Your customer's organization needs a new system running on the same platform as its existing systems—Windows Vista Business.
- Purchase a PC with Windows 7 Professional preinstalled.
- Downgrade—at no additional cost—to Windows Vista.
- Another compelling reason to encourage customers to move to Windows 7 is the ability to downgrade to Windows XP.
- Move to Windows 7 Professional at the appropriate time. The system is licensed and ready for conversion.
I believe Barman is right. It is ONE key with which you can run either XP or win7 - not both at the same time.
The passages quoted above say nothing about the legality of running both at the same time.
So, what are Windows Vista “Downgrade Rights”?
Windows Vista Business and Windows Vista Ultimate have what Microsoft calls “Downgrade Rights.” Downgrade Rights means that anyone with a Windows Vista Business or Windows Vista Ultimate operating system can downgrade to Windows XP Professional provided they have the media for Windows XP Professional. Customers may use one operating system at any single point in time (cannot run both operating systems simultaneously unless an additional license is purchased). For customers who decide to exercise Downgrade Rights on their own, however, please note that Dell will only support the factory-installed operating system. Windows Vista Home Basic and Windows Vista Home Premium do not have this option, as they are not capable of downgrading to Windows XP.
End users may reinstall the software at any time provided the downgrade operating system has been removed from the computer, and that software is reinstalled on the same PC on which it was originally installed, using the original OEM system builder edge-to-edge media distributed with the original PC. The end user will need to use the product key, located in the center of the Certificate of Authenticity (COA), in order to activate the following products:
I think we are puzzled about the semantics of the word "use". I always read that as "installed". But maybe that is not right.Customers may use one operating system at any single point in time