@mikrolactaki3 Assuming you installed your Sims 3 games from Origin, it is possible. Open your Origin library, right-click on The Sims 3 tile and select Move Game. Then you can pick the new location. As for your saves, they shouldn't be affected, but it never hurts to have a backup. However, if you made any modifications to your Sims 3 installation folder (GraphicsRules fix, fixed worlds, etc.), back them up because Origin might undo them.
@mikrolactaki3 It's fine to install on D, either with your discs or, if the packs are all registered in your Origin game library, by downloading directly from Origin instead. However, in either case, you'll need to clean your computer's registry either manually or with a tool like Piriform's CCleaner (the free version is fine) before reinstalling. Otherwise, the leftover registry entries from the previous install can prevent the game from launching once you reinstall.
If you'd like to look for the registry entries yourself, here's a guide to finding and removing them, under the instructions for a manual uninstall:
https://help.ea.com/en-us/help/the-sims/the-sims-3/manually-uninstalling-the-sims-3/
Be sure to back up your registry first, since deleting the wrong entry can prevent your computer from working at all.
