Your totally correct Dave, I copied the wrong code to the NG, this is
what I should have shown Doh!

Sub UncheckBoxes()
Application.ScreenUpdating = False

Sheets("Input").Activate
For Each ctrl In ActiveSheet.OLEObjects
If UCase(TypeName(ctrl.Object)) = "CHECKBOX" Then
If ctrl.Object.Value = True Then
ctrl.Object.Value = False
End If
End If
Next
End Sub