You should change the screen resolution of your display. In most of the cases, the apps running on the screen will adjust themselves to fit on the screen or you could press the Windows + P and use different displaying options, then switch it back and again the windows will re-arrange themselves automatically.
I wouldn't recommend tampering with the configuration files, because in the end you'll have to reinstall the application again.
In case that happens, download the installer from the official website: https://discover.aol.com/products-and-services/aol-desktop-for-windows
