Sims 3 wont install!! WHY!?

Okay well. Ive had the game for awhile and i had to uninstall the game because it wasnt working properly so i figured if i unistalled it and then installed it again, it will work BUT its installing as we speak for about 6 or 7 hours now and the bar where it tells you how much download is left to install or whatever, is complete but its not doing anything. Itll keep coming up error things and ill click "retry" and the letters above the bar that tells you how much it has left to download will like change up and it did that about 10 times now. Can anyone help me or am i out of luck completely?