From the title of your post, it sounds like you want to uninstall the base game. Unfortunately, you can't do that unless you uninstall all of the games. You can uninstall each expansion pack after the base game, but just not the base game. Yes, you can put saves or folders on the desktop in a folder and if you do reinstall your games, you can put them back in. I used a thumb drive and it worked perfect, either way is fine. If you have anything from the store, you can just go to your purchase history and reinstall those items.