Nope, I don't think you are going to have much luck with that approach.
If you have two network cards in one of the computers (or can add a second card) your best bet would probably be to use.... Internet Connection Sharing
As I said originally, I don't think so. Most if not all ISPs provide (unless you pay for more) one single IP address and it is applied to and identified with a particular MAC address. So even if you could somehow manage to clone the MAC address of one to the other the network would go toes up if you tried to use them simultaneously since Media Access Control addresses need to be unique on a single network.
You can of course try anything you want to try, it's your equipment, but I can tell you that it will not work reliably, because MAC address have to be unique on a single network segment (broadcast domain) or the return packets will not be able to determine the proper return path. You'll almost certainly begin getting errors right away.
Yes your right. I changed the comp2 MAC to match comp1 through registry and my comp actually detected comp1's network adapter for a second. Both computer now say theres internet, but comp2 won't load websites etc.