To start GTA V through Steam:

1. **Make sure the Rockstar Games Launcher is closed** completely by exiting it from the system tray[1][2].

2. **Open Steam** and go to your library. Right-click on GTA V and select "Play"[1][2].

3. **If the Rockstar Launcher opens but GTA V doesn't start**, try verifying the game files in Steam:
- Right-click on GTA V in your Steam library and select "Properties"
- Go to the "Local Files" tab and click "Verify Integrity of Game Files"[2][3]

4. **If you still have issues launching the game**, try clearing the Steam download cache:
- In Steam settings, go to the "Downloads" section
- Click "Clear Download Cache" and restart Steam[2]

5. **As a last resort, try launching GTA V directly from the Steam folder**:
- Exit Steam completely from the system tray
- Navigate to your Steam\steamapps\common\Grand Theft Auto V folder
- Run GTAVLauncher.exe as an administrator
- The Rockstar Launcher should open with the "Play on Steam" option

If none of these steps work, there may be an issue with your specific installation. Make sure your system meets the game requirements and try reinstalling if needed/