Gta 4 runs well on my pc, but I am not sure Why some options in graphics tab are missing... Like Shadow quality, Reflection resolution, Reflection quality, etc:-
This bug can be fixed by installing Patch 8 for GTA IV and/or Patch 3 for EFLC or any later update, including The Complete edition. From the download page for Patch 8:
Fixed a bug that restricted settings changes when using modern video cards.
For the Steam edition, you should have The Complete Edition with IV, TLAD and TBoGT combined. If the game is updated and you are not running the latest version, check the integrity of the game:
- From the Library section, right-click on the game and select Properties from the menu.
- Select the Local files tab and click the Verify integrity of game files... button.
- Steam will verify the game's files - this process may take several minutes.