GTA IV is an older game, and it can sometimes have trouble starting on modern PCs. Here are some of the most common issues and their fixes.
The community has built two tools that completely replace the broken launch logic: download launch gta iv exe link
Why would someone want an older EXE file? Because due to expired licenses, and many mods (like ENB Series or FusionFix) simply do not work on the latest patch (1.2.0.43 or higher). GTA IV is an older game, and it