Mass effect troubles

hi guys i just bought mass effect 1 for my new computer and whenever i go to install it stops at the same point every time i have extracted all the rar files but 1 rar file doesnt extract it just stops. can any1 help me

As DanielDust says no legal copy of a game will ever have you messing about with RAR files, if you are having to unrar stuff to play your game then it is highly unlikely that is a legal copy of the game.