Not much info to go on there, care to help me help you.
What happens when you try and start your a new game?
What happens when you try and load your existing game? and the autosave?
What happens when you try and uninstall?
...
What happens when you try and start your a new game?
What happens when you try and load your existing game? and the autosave?
What happens when you try and uninstall?
...