Modders specifically hunt for older versions of LaunchGTAIV.exe (like 1.0.7.0 or 1.0.8.0) because each version handles memory differently.
Simply having the EXE is not enough. The game needs to run in a modern environment. Do this checklist: Download Launch Gta Iv Exe
: Open your Steam Library, right-click on Grand Theft Auto IV , select Manage , and then click Browse local files . This will open the folder containing the GTAIV.exe . Modders specifically hunt for older versions of LaunchGTAIV