Removing duplicate objects from collection

Hello, I have been bashing my head on the desk for a few days now with little luck in learning something.
I have a collection that contains System.IO.FileInfo objects. This collection populates a GridView (2-columns: "Name" and "LastWriteTime").  I do not want duplicate objects.  I can sort my collection.

How can I remove duplicate objects from the collection before or after databinding it to the GridView?  Below is my recursive loop that gathers the files and places them, as objects, into my collection.  I pass the path to this procedure, then databind the collection to the GridView.

    Public Sub Search(ByVal FullPath As String)
        Dim currDirectory As New DirectoryInfo(FullPath)

        'Each filter gets its own If/Then For/Each Statement

        If txtOrde ...