If your Xbox pops up a window, select Cancel to continue with these steps.
You should see your internal storage on the left side of the screen and your external storage on the right side. If you see only your internal storage, your Xbox One does not detect your external drive. Make sure it’s at least 256GB and that it is plugged in correctly. If you can, try a different USB cable.
If you opt to use your internal storage as default, your Xbox One will use the internal storage until it’s full, then start using your external.
If you opt to use your internal storage as default, your Xbox One will use the internal storage until it’s full, then start using your external.