GTA2 stuck at 640×480? Try this
On some systems (not mine), GTA2 refuses to run at 1024×768 or any resolution higher than 640×480, even if you select a higher resolution in GTA2 Manager. Siwu has created a patch to work around this problem. The patch is for the free (9.6F) GTA2 exe file (this one is the most popular). You don’t actually see more in higher resolutions since GTA2 just stretches the image.