To Hide a Standard Explorer Context Menu Item

In the Customize dialog ( File > Settings > Configuration > Customize ) on the Tools tab, expand the Explorer Context Menus tab.
Expand the open DGN library.
Do one of the following:

Select the open DGN library and click the New Menu Item icon to add a context menu item to it. Make sure that the context menu item has the exact name of the standard context menu item that you want to hide.

or
Select a context folder and click the New Menu Item icon to add a context menu item to it. Make sure that the context menu item has the exact name of the standard context menu item that you want to hide.
Select the custom menu item and in the Properties pane, set the Priority field to Common.
(Optional) If the Show/Hide Test property is not visible on the General Settings tab, right-click the tab and select Add Show/Hide Test.
Do one of the following:

Set the Show/Hide Test field to None.

or
Select a named expression or an in-line expression.

Note: If you select a named expression or an in-line expression, the standard context menu item will be hidden only when the selected test evaluates to True.
In the Properties pane on the Command Data tab, delete the text from the Key-in field.
The standard menu item no longer appears in the Explorer context menu.