Unable to uninstall halo insider flights properly

I’m having a problem with the halo insider flights where I can’t uninstall them through steam as they are not in my steam library. Using the control panel to uninstall the flight does nothing. I have deleted the main folder which holds the bulk of the space for the one of the master chief collection flights, but the flight still shows up in the installed programs in Windows 10. I’m also pretty sure there are a bunch of other small files such as the screenshots folder that aren’t deleted. My friends still have the flights in their library, but they take up little space on their drives. I looked at some other forums and I think this is because there was an update that uninstalled the game for you, but for some reason, I didn’t get that update. I’m the type of person that closes steam when I’m not using it so maybe I missed the update.