A few months ago when I was trying to reinstall Battlefield 4 and Hardline on my system with Steam I kept running into a problem where it would stop downloading at around 70% and never finish. In my search for a fix I found a user on Reddit that also had this problem trying to install Elden Ring on their Windows 7 system. The solution was using SteamRE DepotDownloader to download the game files instead and move all of them manually to the game directory in the Steam apps common folder. Steam will validate them and should finish downloading whatever was missed. My Steam version for reference: