Is that possible, different maps with the same FID and different PID? I thought only one Family ID can be used in Mapsource. btw, I tried to adapt the template but mkgmap can't find it, where do I have to put installer_template.nsi? I've tried it in a resources folder and in resources/installer but that doesn't work. About the language, the programm asks what language to use, English/French. Then it detects there is an old version already there, the uninstaller pops up, asking again what language you want to use. Maybe it is possible to skip this double check? Thorsten wrote: currently, $REG_KEY will be used to determine if the map is already installed. But $REG_KEY is not unique, if you have several maps with the same family-id, but different product IDs.