I see you guys need help....
1) Open Steam
2)Right click GTA4 in the game list
4)Click on "Set Launch Options"
5)Enter the following without the double quotes "-availablevidmem 6"
Note: i use 6 because i have 12GB of vid memory, you can change this to anything you want, it represents the amount of Video Memory you have in Gibs so -availablevidmem 6 means i have 6 giga bytes of video memory remaining.
Also ever want to run the game in a window follow the steps above and add "-windowed" in the launch options. If you have multiple options it should look like this.
-windowed -availablevidmem 6
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