Actually, I think the one you are trying to download is outdated, although it would still work I recommend you download both these files instead:
www.pandoraonline.net/installers/hero_full_installer.zip
www.pandoraonline.net/installers/hero_full_installer.z01
Make sure both have finished downloading + are in the same folder before you extract. You will need an extracting software, such as WinZip.
These 2 files I'm making you download are actually 1 file, but split into 2 to make them easier to download, which is why you need both, they don't work separately. If it works, you should be able to extract a .exe from them and run that to install heRO in a fresh folder.
