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what Windows You using. Try deleting gta_vc.set (C:\Users\(YOUR PC-NAME)\Documents\GTA Vice City User Files) or goto the folder where Your Vice City is installed, right click on gta-vc.exe > Compatibility > tick "Run this in compatibility mode for" and change to "Windows XP (Service Pack 3)" if this options don't fix it, revert this to default or just remove the tick from "Run this in compatibility mode for".