I am trying to install UE thru the Launcer but it keeps trying to install to a drive that does not have enough room and it won’t let me choose a different drive (even though it keeps telling me too) Anyone else ever have this problem? And everytime I delete the installer and try to start over it still AUTOMATICALLY chooses the same wrong drive which is not even my C drive!!! I am so done with UE!!!
Does changing the Vault Cache Location help?
(“Settings > Edit Vault Cache Location”)
Otherwise, not sure 
The Epic Games Store & Launcher help link is probably a better option for help with the launcher in its current state.