HEEELLLPPPP!!! PLEASE - error while uninstalling

Ok so i have been having problems trying to update my game so i decided that i would uninstall my sims 3 game and then re-instal it to see if that woulkd fix the problem but it wont let me uninstal my game . it says that there is a error, please make sure you have finished any previous setup and closed other applications. I was wondering if anyone could tell me why it is doing this as i am completly confused