"We are aware that a small number of fans are having problems running GTA IV
on their PC's and we would like to assure them we are working to help solve these as quickly as possible," comes a statement
from Rockstar, shortly after several players reported encountering problems running the open-ended crime caper. While the developer works on tracing issues like crashes and missing textures, the game's official support page
asks "anyone that is encountering difficulties to contact their local technical support helpline for advice and recommendations. These telephone numbers can be found in the game's manual."
The support page currently offers information on several known issues and other relevant advice. For instance, are you getting the "Application Failed to Launch" error? Well, the solution is simple! "Make sure you can run GTA IV."
[Via Big Download