If there is a folder in File Explorer opening when you log in, that’s not a program. The folder could be a leftover startup entry. So, you can’t find it in the Control Panel. The folder opening on startup may be caused that you accidently put a shortcut in the wrong place in your start menu. When you login in, the shortcut will try to execute. If the file is removed, but the shortcut is still there, a folder may automatically open. So, you can choose to remove it.