Steam has most PC games, but it doesn't have them all. You'll need to know how to add external games to your Steam library to have your collection in one spot.

This tutorial shows how to create a new Library or add, remove or delete a folder in Windows 11/10 Library Navigation Pane.

You can Add or Remove one or more Libraries from File Explorer Navigation Pane in Windows 11/10 via Explorer, Folder Options or Registry.