Once installed, right-click the game in Steam > Properties > Local Files > Verify Integrity of Game Files to ensure no data was corrupted during the 22GB download. If You Are Installing from a Retail Disc: Insert Disc 1: Follow the on-screen prompts.
-availablevidmem 4096 (Replace 4096 with your actual GPU VRAM in MB) -nomemrestrict -norestrict -percentvidmem 100 Save and exit. Install FusionFix
Navigate to your GTA IV install folder (e.g., SteamLibrary\steamapps\common\Grand Theft Auto IV\GTAIV ). Create a new text file named commandline.txt . Paste the following lines: