The Downloads window is gone in Firefox 26. The browser.download.usetoolkitui preference has been removed. If you still see it in about:config, it's because you previously customized its value. Right-click it and choose Reset; it will be gone the next time you start Firefox.

I believe the plan was always to replace the Downloads window with the Downloads Panel and the Library category. Since its code hadn't been maintained, it had several issues, like incompatibility with per-window private browsing.

If you have suggestions for improvements to the Downloads Panel or the Library category, you can file enhancement bug reports.

• https://developer.mozilla.org/en-US/docs/Mozilla/QA/Bug_writing_guidelines

You can also try the following add-on.

• https://addons.mozilla.org/firefox/addon/downloads-window/

Thank you for your answer :)

best regards

Screw the incompatibilities, fix this, and get rid of the other elements that are causing the problems. Who ever uses private browsing? Not me. How about a fork of this that DOES work properly like FFx 3.6 or below. Everything since 4.0 has been crap.

Mozilla, if a large number of people use a feature to the point that they are digging in to the configuration to re-enable it when you turn it off my default, please don't remove the feature altogether. It disrupts users' browsing experience and upsets them.