Windows Collection
Includes a Window object for a window that is open in the application.
Remarks
To retrieve a Windows collection, use the Windows property of an Application object or a Window object.
The default property of a Windows collection is Item.
If your Visual Studio solution includes the Microsoft.Office.Interop.Visio reference, this collection maps to the following types:
Microsoft.Office.Interop.Visio.IVWindows.GetEnumerator() (to enumerate the Window objects.)
Microsoft.Office.Interop.Visio.IVWindows