Re: The Sims 3 - Transferring saved games from Mac to PC
@NovaScotia1867 Yes, you can certainly transfer your content from one computer to the other. In fact, you could theoretically move your entire TS3 game folder over and just pick up right where you left off. However, it's better to launch the game on your new computer, generating a clean game folder, and then copy over the content you want to keep. That way, you'll get rid of stale cache file data and any extraneous files you don't need.
The only files you won't be able to use in Windows are any core mods you have. A core mod has to match the patch level of your install, so unless you're installing in Windows via disc, you'll need to download new versions of any core mods you have. You can check with the mod sites, but there are only a handful of core mods in existence. The best known is ErrorTrap, but all other NRaas mods (aside from UntranslatedKey) are scripts and will transfer fine.
You may also need to redownload and reinstall your store content. It's supposed to be transferable between an Origin/mac install and Origin/Windows, but it doesn't always work. Rather than risking corrupt store content files, it may be better to just start from scratch.
The best practice is to spawn a new game folder, copy over or reinstall all of your mods, store content, and cc, and then test out a new game to make sure everything works properly. Once you're satisfied, you can move over your existing saves as well as any households or lots you'd like to have available—every entry in the Edit Town bin has a corresponding file in Library. For a complete explanation of everything you find in your game folder, you can check out Crinrict's guide: