If your like me, GTA IV was running great since I purchased it on steam (many months ago). Then all of a sudden it would crash as soon as the loading screen characters disappeared ! Well, after a month of forum surfing I finally found the one thing that worked. I tried EVERY SINGLE THING YOU COULD THINK OF. Literally...... Anyway, after much work, the only thing that got me running again was installing and uninstalling Quicktime. I never had it before (QT) but for some crazy reason this worked. Hope this helps you guys and gals struggling to play.