Option Explicit

Sub HyperLinkSearchReplace()

    Dim oSl As Slide
    Dim oHl As Hyperlink
    Dim sSearchFor As String
    Dim sReplaceWith As String
    Dim oSh As Shape

    sSearchFor = InputBox("What text should I search for?", "Search for ...")
    If sSearchFor = "" Then
        Exit Sub
    End If

    sReplaceWith = InputBox("What text should I replace" & vbCrLf _
        & sSearchFor & vbCrLf _
        & "with?", "Replace with ...")
    If sReplaceWith = "" Then
        Exit Sub
    End If

    On Error Resume Next

    For Each oSl In ActivePresentation.Slides

        For Each oHl In oSl.Hyperlinks
            oHl.Address = Replace(oHl.Address, sSearchFor, sReplaceWith)
            oHl.SubAddress = Replace(oHl.SubAddress, sSearchFor, sReplaceWith)
        Next    ' hyperlink

        ' and thanks to several astute user suggestions, let's fix OLE links 
        ' and movie/sound linkes too
        For Each oSh In oSl.Shapes
           If oSh.Type = msoLinkedOLEObject _
            Or oSh.Type = msoMedia Then
              oSh.LinkFormat.SourceFullName = _
                   Replace(oSh.LinkFormat.SourceFullName, _
                   sSearchFor, sReplaceWith)
           End If
       Next

    Next    ' slide

End Sub