Do I need two Windows 7 CD's?

[win123454321]

I've recently purchased a new laptop with Vista home premium and will receive free Windows 7 upgrade. I'm also going to purchase a new desktop. It costs $50 to upgrade form Vista home basic to Vista home premium. Can I just have my desktop use Vista home basic and save the $50 since I will already be getting a Windows 7 CD from my laptop purchase anyway?

 

[Bodaggit23]

I have a feeling that when you get the Upgrade Coupon, that's it's for a generic
copy of Windows 7 Upgrade, which would work on ANY computer, as long as that computer has an Activated version of Windows already installed.