How to fix Steam error not recognizing installed games

What is Steam error -102? What should I do if I encounter an error that I cannot open the game on Steam? Below is the troubleshooting guide for you.

The Steam client has a built-in backup and restore feature, helping users create a backup of their existing Steam library and restore game files from that backup.

People can also create a backup of the game installation folder manually and restore it after performing a clean install. However, after a clean install or restart, Steam may not recognize installed games and prompt to reinstall the application.

This is an issue that has occurred multiple times and is reported to appear on both Windows 11 and 10 computers. Luckily, users can tell Steam to locate their games from the installation folder with a little tweaking. Below are ways for Steam to identify games installed on your PC.

Reinstall the game to play without downloading it

According to Steam, some games may appear as not installed if the installation files are not recognized by the Steam client. Provided the game folder is in the correct location, users can begin the download process. This will force Steam to recognize existing installation files without redownloading them all.

Note that this requires logging into a Steam account and following these steps to reinstall the game in Steam without downloading it:

Step 1: Open File Explorer (Win + E) and navigate to the following location:

C:\Program Files (x86)\Steam\steamapps\common

Step 2: Make sure that the folders associated with the affected games exist in that location.

Step 3: Launch the Steam desktop app on your PC and sign in to your account.

Next, make sure not to be in Family View mode by clicking Family View icon in the top right corner of the screen and Enter your PIN.

Step 4: Open a tab Library in the top left corner, where you list all the games you own and install on your PC.

Step 5: Select the game with the error and then press the button Install.

When Steam starts installing the game, it will likely recognize the existing files and complete the installation without redownloading all the files.

Add an alternate install location

Users can change the default Steam game download location to save large games on a different drive. If games have been previously moved, Steam will not be able to find the files and show them as uninstalled. To fix this, add alternate game folders to the Steam client using Steam Manager.

Step 1: Launch the Steam client and make sure to exit Family View mode.

Step 2: Next, click Steam in the top left corner and select Settings.

Step 3: In the window Settingsopen the tab Download.

Step 4: Click STEAM LIBRARY FOLDERS in Content Libraries.

Step 5: In Storage Managerclick the icon + next to existing storage locations or drives.

Step 6: Tap the drop-down menu in the box Add a New Steam Library Folder and choose Let me choose another location.

Step 7: Browse your storage drives and select the Steam game folder you want to add.

Step 8: Finally, press the button Select to add folders.

Step 9: Steam will search for files in the newly added folder and display them in the Steam library. If the game doesn’t appear, relaunch the app and check your Steam library.

Manage .acf files for Steam games

Steam .acf files are used for data storage and configuration caching. Essentially, each .acf file has a unique application identifier (App ID) and stores game information such as installation status, additional content (DLC) download status, build ID (Build ID), and other user preferences.

If the .acf file associated with a Steam game is missing or damaged, Steam may not be able to recognize installed games. To fix this problem, you can move existing .acf files out of the folder and then put them back in; This will force Steam to re-recognize installed games. Before you begin, make sure you have enough disk space to install the game you downloaded on Steam.