@dreamystarbi I would suggest installing Everything, from VoidTools, which is a free and highly-efficient search tool, much better than the built-in Windows search. This will speed up the process of looking for a second install, and also give you more confidence that one doesn't exist if you don't find anything.
Launch Everything and search for TS4_x64. You should see exactly one result, or two if you have a desktop shortcut to it. If you see multiple results directly inside a Bin folder, please post the full location of each Bin folder, which you can see by expanding the window sideways.
If you only see the one result, look for Delta, which is not exclusive to Sims 4 but may exist when TS4_x64 does not. If you see multiple Delta results that are directly inside a "The Sims 4" folder, post their locations too. Finally, please search for __Installer and post multiple results that are somewhere inside a Sims 4 folder, if they exist.