put visualSettings.dat in 

GTA IV
C/Program Files/Rockstar Games/Grand Theft Auto IV/common/data

GTA EFLC
C/Program Files/Rockstar Games/EFLc/common/data
C/Program Files/Rockstar Games/EFLc/tbogt/common/data
C/Program Files/Rockstar Games/EFLc/tlad/common/data