win8 downloaded / win7 none activation

When Win 8 was released I bought it as a download from Microsoft this included the product number, I now want to load it in a new laptop, I first have to install my win7 but I can't use the 7s product number cause that's being used in my other laptop.
If I load win7 without activating it, then load win8 and activate that what will happen after the 30 days of not activating win7 ???

Did any of that make any sense ???

Your Windows 8 install will become invalid after 30 days. You need to purchase a license, if you wish to continue using. Windows 7 licensing has nothing to do with 8. Same with 8 has nothing to do with 7.

How do you download Windows 8.1 and clean install Windows 8.1, if you have a Windows 8 product key? -> link

See here: http://www.eightforums.com/tutorials/13375-clean-install-windows-8-upgrade.html