Indeed, since version 6, the setup.iss method is not working anymore. I've been searching allot, trying to find out the new method but it seems that there's no method anymore. The new version can't be installed silently. So, the only solution which works perfect for me is to backup your already installed eudora folder and export the registry keys from HKEY_CURRENT_USER\Software\Qualcomm. Make a batch command for your unattended install which copies your backed up folder to your program files directory and run your exported .REG key. Because i'm using the non-pro version, I can't tell you if your version will be registered immediately with this method. At least it has to be able to run. When I look at the files and the register, I think there's a big chance that it will be installed as being registered immediately with my method. In the worst case, you'd only have to register it again when running for the first time. Good luck!