Cuz I Can

I am having a problem with the sims 2 that everyone else seems to have. I paid 50 dolars for a defected game,.. none the less i want it to work. I dont understand how to make it start, i already installed it, something keeps popping up about direct x 9.0 o something. People that have found the cure to this problem wrote thier directions, but i still dont know WHAT the mess they are talking about. Can ANYONE put this in english