I had two folders in steamapps\common named as follows:so you just renamed the game folder you wanted to use to the original name?
so for PES 19, I would just rename the game file I want to use to 'PRO EVOLUTION SOCCER 19?
- Pro Evolution soccer 2017
- Pro Evolution Soccer 2017 PTE
Had I wanted to launch the "vanilla" game, I'd have had to do nothing apart from launching the game via Steam.
Had I wanted to use the PTE version, before launching the game I would have added the "VAN" after the default folder and removed the "PTE" from the other one (both in steamapps\common and in the documents) then I would've launched the game via Steam.
Once done, I'd manually rename the folders back as they were.
I think that it could also be automated, but I never felt the need (OK, never had the will) to do that honestly.
OK, I got a little confused with the grammar and the tenses but I think I still managed to get the idea through, or at least I hope.