GTA-4 EFLC crash on start up

i have just installed gta-4 EFLC.i defraged,validated,and restarted.and still no luck.eveytime i start the game it crashes to desktop after the copyright screens.i have not been able to patch the game becuase of this.does anyone know what might be wrong.

p.s. i have not put any kind of mods in the game yet.never got it luanched.