The short answer is, of course, no one knows. It’s likely that the computer will simply not work after the forced upgrade. I’m telling people that the thing to do with older machines is to run a version of Linux. You can’t run Windows on it anymore, so if you can get some life out of it with Linux, that’s better than just tossing the thing out. (or, of course, you can always give it to me…)
Zorin OS seems to be the new hotness for people switching from Windows 7. I haven’t had a chance to use it yet. Linux Mint is a good choice for beginners, too. Elementary is just beautiful. The good news is, you can try as many as you like!