Hello, 

You can set the FileMenuStyle property exposed from the Ribbon to 'None'. But first you have to set the Office2007UICompatability to 'False'

For more details please visit our documentation:
http://help.infragistics.com/Help/Doc/WinForms/2013.2/CLR4.0/HTML/WinToolbarsManager_The_Ribbon_Application_Menu.html 

this.ultraToolbarsManager1.Office2007UICompatibility = false;
this.ultraToolbarsManager1.Ribbon.FileMenuStyle = Infragistics.Win.UltraWinToolbars.FileMenuStyle.None;