I have a Dell laptop with a genuine OEM Windows 7. I don't want to upgrade it. I have purchased a new machine without an OS pre-installed.
Can I use a Windows Upgrade Offer With the Dell Windows 7 OEM key to install Windows 8 on my new machine?
The upgrade offer is tied to a Windows 7 PC purchased between 2 June 2012 and 31 January 2013, but you can choose to redeem the offer and install the upgrade on any compatible Windows-based PC with a qualifying base operating system
ie your answer is 'No'.