TheBillyAB

Browse to the game folder so for steam it will be something like "C:Program Files (x86)SteamSteamAppscommonGrand Theft Auto IVGTAIV" Right Click on GTAIV.exe and go to properties, then go to the compatibility tab and tick the box that says 'Run this program in comparability mode for:' and choose windows 7 from the dropdown, and tick the box that says 'Run this program as an administrator. For the LaunchGTAIV.exe Right click it and choose 'Troubleshoot Compatibility' On the box that comes up choose 'Trouble shoot program' then tick the boxes 'The program worked in earlier versions of windows...' and the 'The program requires additional permissions' then click next, choose 'Windows 7' from the list then click next, Click 'Test the program' and then click next then click 'Yes, Save these settings for this program' Hope this helps, PM me if you want me to help you remotely. Billy

Try running your game in compatibility mode for windows 7 and as an administrator, It needs to be on the GTAIV.exe and the LaunchGTAIV.exe.