It won't work. There are technical and legal reasons why that idea won't work, all of which have been discussed numerous times before.
I have a flight sim (FSX) that just doesn't want to work on Win 8, or let me say I haven't figured out how to make it work, as some of the guys on a flight sim forum seem to have made it work just fine...however; not me.....
But, I have a laptop with Win 7 and it worked with out problems on that...albeit; like you might imagine it might on a laptop even with a free standing video card...it just wasn't the same, thus my purchase of the Asus pc. But I never considered that Windows 8 might be such a problem.
Now as the subject line suggest, someone who seemed to be knowledgeable in the local BB store (a customer) said why don't you make a rescue disk from the laptop, partition the pc (win8) and install Win 7 from the rescue disk.
I hate to screw up the pc and have to start over...what do you guys think, is this a reasonable fix?