Easy installation. Download, and open it with 7zip, go into the 32x folder and extract 'd3d9.dll and 'dxgi.dll' into the GTA IV folder where the exe file is located. One thing worth mentioning is that it will default the game to 800 x 600 and make the game think you only have 512MB of VRAM.
Support Home Service Status Submit a Ticket @RockstarSupport. Question: What are the system requirements for GTAIV PC?Answer:Minimum:OS: Windows 7 64 Bit Service Pack 1, Windows 8 64 Bit, Windows 8.1 64 Bit, Windows 10 64 BitIntel Core 2 Quad CPU Q6600 @ 2.40GHz (4 CPUs) / AMD Phenom 9850 Quad-Core Processor (4 CPUs) @ 2.5GHzMemory: 2GBFreeStep 2. In the Properties window, navigate to the Compatibility tab and tick the checkbox next to Run this program as an administrator. Step 3. Click on OK and Apply to execute the change.