Steam has a couple of scripts that are executed after the installation of a Game or Program. They say what else needs to be installed or what registry keys need to be created. Some examples:

  • Just Dance 2017 installs Uplay, declared in "steamapps\common\Just Dance 2017\Support\Installerscript.vdf"
  • GTA IV creates "HKEY_LOCAL_MACHINE\SOFTWARE\Rockstar Games\Grand Theft Auto IV", declared in "steamapps\common\Grand Theft Auto IV\GTAIV\installscript.vdf"

Is there a way to force Steam to run the post installation scripts again?

2 Answers 2


From https://partner.steamgames.com/doc/sdk/installscripts :

The install script is marked in the depot manifest. You can see this in the generated manifest.txt file as a 100 in the Flags field.

When a Steam user is starting a game, Steam will scan all of the mounted depots for that game for any file with the install script flag and run them.

From what I understand, you need to find that manifest.txt file for specific game and update this Flags field back to initial value (100).

This answer suggests that for each dependency Steam may actually create a registry entry, which means it may be required to clean the registry before trying to relaunch install scripts.

And it also works only for Windows:

NOTE: Install script functionality described below is primarily for Windows operating systems. MacOS support is limited to file permissions and symlinks. There is no Linux/SteamOS install script functionality at this time.

Unfortunately, I don't have Windows machine right now and cannot validate this.

  • 1
    This information is outdated by years (why Valve). Steam no longer uses manifest.txt for game information, being replaced by appmanifest_APPID.acf (for example, appmanifest_550.acf for Left 4 Dead 2).
    – Lemon
    Apr 21, 2020 at 19:14

I don't think so, maybe go to the game's properties (on Steam) and go to the local files tab and click on the verify Game files. It'll basically see if any files are missing and u can choose if you would like to reinstall them.

  • I already have the complete game, checking the integrity of them will just be a waste of time. Running the files manually is not possible for some games (for example, installing Easy Anti Cheat for Sword Art Online Fatal Bullet).
    – Lemon
    Apr 21, 2020 at 18:42

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