Hello Bengt.

If this "Favoriter" is an extension, make sure it's installed and enabled (Tools > Add-ons > Extensions). If it is and it's still not showing, contact its author for support.

In any case, you should read this support article:

https://support.mozilla.com/en-US/kb/How+to+customize+the+toolbar

I hope it helps.

If you have a problem with the bookmarks then see: http://kb.mozillazine.org/Lost_bookmarks ---

* If the menu bar is hidden then press and hold the Alt key down, that should make the Menu bar appear (Firefox 3.6 on Windows) (see Restore the Menu bar in Firefox).
* Make sure that you have the Navigation Toolbar and other toolbars visible:  View > Toolbars .
* If items are missing then see if you can find them in the  View > Toolbars > Customize  window.
* If you see the item in the Customize window then drag it back from the Customize window to the Navigation toolbar.
* If you do not see that item then click the  Restore Default Set  button in the View > Toolbars > Customize window.

See also Back and forward or other toolbar buttons are missing and Customize Firefox controls, buttons and toolbars See http://kb.mozillazine.org/Toolbar_customization