One of the most overlooked features is the asi_loader.log file it generates. If your game crashes, you can open this log and see exactly which ASI file failed to load. This is a lifesaver for debugging.
A common question: Will this get me banned? gta vice city ultimate asi loader
Extract the dinput8.dll file and place it directly into your main GTA Vice City installation folder (where Gta-vc.exe is located). One of the most overlooked features is the asi_loader