When you execute this installer, it might have taken the default path of DFM in the first screen, something like "C:\Program Files (x86)\NetApp\DataFabric Manager\DFM". Just check it whether your installed DFM path is same one or not. if it's different one then change the path by browse it.
Hope it helps you..!
Re: Using 'wfa_oc5setup.exe' with OnCommand Unified Manager 5.1 (Windows)