To turn off dynamic menus in Excel, first open the Excel application. Then, click on the "File" tab in the top-left corner of the screen. Next, click on "Options" in the drop-down menu. In the "Excel Options" window that appears, click on "Advanced" in the left pane. Scroll down to the "Display" section and uncheck the box next to "Show dynamic menus". Finally, click on the "OK" button at the bottom of the window to save your changes.