In the GTA IV modding community, dsound.dll is often used as an "ASI Loader" to enable mods. However, the modern Steam/Rockstar version (The Complete Edition) often crashes when it detects this file.
If still broken, and apply Patch 1.0.7.0 (or 1.0.8.0) – newer patches improve compatibility. gta iv dsound.dll error fix
Ensure you do not have both dsound.dll and xlive.dll in your main GTA IV folder, as they often conflict. In the GTA IV modding community, dsound