Thank you, that seems to fix the problem.
There is, however, a new problem. I am getting ten errors that look similar to this here:
Pong.obj : error LNK2019: unresolved external symbol "public: void __thiscall sf::Window::Display(void)" (?Display@Window@sf@@QAEXXZ) referenced in function _main
I apologize for these mundane questions. This is my first time using any non-standard libraries, and I am learning it all by myself.