Extract the zip file and replace the original HkShip.exe executable inside the primary game installation folder ( ...\Steam\steamapps\common\SleepingDogs\ ).
Because the game is technically rendering at 16:9 but being stretched by Windows to 21:9, the UI thinks it is in bounds, but you will lose sharpness. This is a last resort. sleeping dogs widescreen fix
Launch the game and press to switch to windowed mode. Extract the zip file and replace the original HkShip