Neil, this could be a potential reason: Not all IsoView files are correctly installed (i.e. can not be found at the right place) or the machine on that the ActiveX control runs does not allow that the ActiveX starts an exe file (IsoEngine.exe). You could download the eval version again, to assure to have it correctly downloaded (compare size with previous download). Then reboot the machine, do not start any IsoView, and reinstall IsoView again. Maybe that already helps. A simple test is to drag and drop an iso file on IE. If it is displayed by IsoView then in general the installation worked well. Much success, Christian