Simple DNS Plus v. 4.00 and earlier used different configuration file formats which are not understood by v. 5.3 and later.
Place this file in the directory where Simple DNS Plus is installed and then run it from there.
It is important that the new version of Simple DNS Plus is installed in the same directory as the old version was.
If you have already run the new version prior to running "upgrade5.exe", it will complain that the v. 5 configuration file already exists. In this case you need to delete the v. 5 configuration file and then run "upgrade5.exe" again.
The v. 5 configuration file will be located in the "c:\ProgramData\JH Software\Simple DNS Plus" folder - or a your Windows language equivalent. Note that "c:\ProgramData" is usually a hidden folder.