hyperlinks in KDE

[icegood]

How to manage KDE to do all links in all windows like "about..." will openable in firefox?

[Frogs Hair]

Hyperlinks built into the operating system are opened with the default browser at least on Ubuntu. If Firefox is not default you would probably need to change it. I test FF Nightly but Opera is my current default so I know the change is possible in Ubuntu.

[drmrgd]

In the System Settings menu, choose the "Default Applications" button. Under that you'll see an entry for "Web Browser" where you'll be able to select Firefox as the default. See the attached screenshots: