I haven't decided if I want to switch from 10 to 7 just yet, abd I'm considering to use a spare SSD to install 7 and switch between 10 and 7 when I want.I'm not sure what you want to accomplish. I guess a oem key from another computer to install Windows 7? OEM key's are almost always bound to a brand and a certain hardware generation. So if you use it on another computer it probably won't activate. No harm in trying though.
So of course, been trying to find ways to activate Win7, but just now I don't feel like doing it... and I don't think I will soon unless I get my hands in another laptop capable of Win7.