If you not made other changes in external tools ( eg. nvidia controll ) which are possible reseted, a re-install wil change nothing. You get the same files on disc and it’s only big waste of time.
Therefore the questions about settings, that we can possible give hints 
The amount and kind of installed Add-Ons are of course one aspect which can lower fps.
Another thing can be vsync… e.g. 25 is the a step(20 in this game) for a 75fps monitor.