My cousin is a Dota2 player and he moved in with me. I mostly play blizzard games so I didn't have steam installed. He brought his steam folder and just copy-pasted the whole thing in my HDD.
Within the steam folder, there was Team Fortress 2 among the game files, as well as Dota 2 and Emily is Away.
I already have played all of those games with my steam account on a different computer, so it would make sense that they appear in my games list, but there is one who doesn't appear: Team Fortress 2.
In case the information could help, last weekend, we had a kinda LAN party at my place, and one of the guests installed PUBG on my computer, and we played with his steam account, and now, when we login in steam with our own accounts, the PUBG is in the library games list, even if we aren't able to play it without purchasing a licence, but that is not part of the problem, just a confirmation that every game that is in the games folder should appear there.
Question What could be done to make Team Fortress 2 appear on the list as well even if it's already in the games directory?