DLL crash for the sims 3 wont let me play?

hi,im a huge simmer but not good with tech stuff i wanted to know f any of you out there could help.okay this is my problem okay so i had half a screen so i though it was the game (sims3)so i deleted it not uninstall deleted!but then my dad prushed a button and now it is a full screen (this screen thing would only happen when i played the game)and now i want to play so badly and i cant bc of this stupied dll crash and if anyone can help i would love u for it.i have a p.c.plz help