Pretty sure its a corrupted save game. Go to Appdata in C: Users and then you. Go into local, rockstar games, gta 4 and saved game. Delete everything in the folder savegame. Note, you will have to restart the game.
Good luck
Dave
I have a question. I installed everything perfectly and even when i run G17, it says i have everything but when i launch the game, it says that GTA 4 has stopped working. A pop up says the data execution prevention has stopped it. Anyone know how to fix that?