By default, the WebBrowser control automatically navigates to documents that are dropped onto it. This behavior is useful when you use the control as a generic browser. If you use the control to display content designed specifically for your application, such as HTML-based user assistance, set the AllowWebBrowserDrop property to false to prevent the display of other content. This is particularly useful when you want to conceal the fact that you are using the WebBrowser control, for example to create a user interface that seamlessly combines Web-based controls with Windows Forms controls.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)