Returns or sets a value indicating True if the specified add-in is installed (loaded).
Assembly: Microsoft.Office.Interop.Word (in Microsoft.Office.Interop.Word.dll)
Add-ins that are loaded are selected in the Templates and Add-ins dialog box (Tools menu).
Uninstalled add-ins are included in the AddIns collection. To remove a template or WLL from the AddIns collection, apply the Delete method to the AddIn object (the add-in name is removed from the Templates and Add-ins dialog box). To unload all templates and WLLs, apply the Unload method to the AddIns collection.