The game has been fine for 100+ hours but now there is a chance of the game crashing every time I open a door to a new area.

I assume I should re-install the game before anything else.

I bought the game as a disc and put it in my steam library - will my save files disappear if I re-install the game?

If so, where are they, and if I move them and then put them back in the right place will the game instantly recognize them?

Thanks. . .