Buying a game that is already installed on my computer

[chopchop]

I have been playing Hollow Knight with Xbox Game Pass. But getting achievements was so satisfying that I also want to buy it from Steam. Do I have to re-install it when I buy or would Steam recognize my game files?
Also would achievements I already got become active when I buy it, or do I have to achieve them from the start?

[Kargor]

Whether or not achievements are given retroactively depends on the game; some games report achievements when you load a savefile that has them, while others do not. It's also possible that some achievements pop up and others don't.

As for the game files, you will have to download the game again. It may be possible to arrange things so Steam sees an installed game with a couple of damaged files, but I've never actually seen a description of how to set things up like that.

[Jaunitta 🌸]

It should be fine since the Xbox version differs from the PC version.
I'd ask in that games discussion hub since players that have played on the Xbox may have also done what your wanting to do.
https://steamcommunity.com/app/367520/discussions/

[NICEgood32]

Originally posted by pie:

I have been playing Hollow Knight with Xbox Game Pass. But getting achievements was so satisfying that I also want to buy it from Steam. Do I have to re-install it when I buy or would Steam recognize my game files?
Also would achievements I already got become active when I buy it, or do I have to achieve them from the start?

You probly have to, I have installed gta 5 on steam and epic games so I think that you have to install it again

[Ogami]

You have to install it again. Gamepass installations are in a completely different format then Steam ones, also hidden by default. They dont even have a standard game exe since all runs over the Windows 10 Store.
Your save games MIGHT work since those are often stored in a common location like your "My Documents" folder.
But achievements and playtime have to be unlocked again from the start for the Steam version.

[Brujeira]

Originally posted by Jaunitta 🌸:

It should be fine since the Xbox version differs from the PC version.
I'd ask in that games discussion hub since players that have played on the Xbox may have also done what your wanting to do.
https://steamcommunity.com/app/367520/discussions/

Think you’ll find that they’re referring to the XBox Game Pass for PC as that’s a thing. They’ll have to download from scratch though as the version in the MS store won’t have any Steamworks code for achievements, trading cards, Steam Cloud, etc.