May 2020
I have Windows 10 and I tried to download Sims 3 multiple times, but it never worked. It always ran for only a few seconds to open Origin to then have that therefore get stuck on the upgrading page, and Sims 3 never got any farther into downloading. I had previously had Sims 3 on my old Windows 8, and thought that might be the problem. But if you're saying it'll work on Windows 10, how do you use Compatibility Mode?? Maybe that was the problem I was facing?
May 2020
@Kaitmcnweb43 I've split your post into its own thread, since the other thread is a few years old.
Sims 3 does run in Windows 10, without any compatibility mode necessary. So please don't use one—it will likely cause more problems than it solves.
What do you mean by "stuck on the upgrading page"? It would help to see a screenshot of where in the process things go wrong, as well as any error messages you get.