C:\Program Files\Mozilla Firefox\firefox.exe If you're using My JDownloader (web interface) to control JDownloader remotely — that runs in whatever browser you open it with . That's separate from JDownloader's own local link opening. Bottom line: Change your OS default browser, or (if you need more control) set a custom command in JDownloader's advanced settings.
It sounds like you're looking for information on how to (for example, to open captchas, links, or my.jdownloader.org). jdownloader change browser
Here's the short answer: It opens your system's default web browser . C:\Program Files\Mozilla Firefox\firefox