File - Get External Data - Enterprise Tools - Clear Window Configuration

Ribbon bar. Select the Home tab. In the File group, click Open. Select Clear Window Configuration from the Open External Data - Enterprise Tools submenu to clear the current configuration (arrangement) of windows (graphs, etc.) and return it to the default operation.

Classic menus. From the File - Get External Data - Enterprise Tools submenu, select Clear Window Configuration  to clear the current configuration (arrangement) of windows (graphs, etc.) and return it to the default operation.