max2 said

What is an avareage gain from such a thing?

I have no idea. What is the average donation you give for free software?

Hi I came across another problem. I use startup pasword, which requires master password to run Firefox. But I'd need a refinement: a Firefox should start WITHOUT this password,but in that case without remembering any history of previous usage, be it visited urls or saved password for www sites. Is this possible? Because otherwise I cannot let anyone else to use my computer. New instalation of Firefox to another directory is not working and installing IE is not a good solution :-(

Hi max2, how would you like it to work? For example, someone sees a Firefox icon on the desktop and double-clicks it and loads into a clean profile that doesn't have any of your information, but you have a different shortcut stashed somewhere else that loads into your real profile?

Firefox does have a Profile Manager that allows you to create separate profiles, and it does have a command-line/startup switch to load a specific profile, so the above scenario is very feasible.

More information:

• Profile Manager - Create, remove or switch Firefox profiles - please be careful not to delete your "real" profile in here because there is NO undo for that.
• https://developer.mozilla.org/docs/Mozilla/Command_Line_Options

This is almost what I want. A better thing would be, that instead of Profile Manager at start-up, two icons, one for each profile,should exist...

max2 said

This is almost what I want. A better thing would be, that instead of Profile Manager at start-up, two icons, one for each profile,should exist...

Yes, you definitely do not want anyone else to use the profile manager. There is a checkbox in the profile manager so that if no profile is specified, Firefox will load the last used profile. Keep that checked. The command line switch you want is the one to specify the profile to use.

Oh, yes, but 2 icons for different profiles are not possible? Left icon loads profile 1, right icon profile 2...

Yes, yes. Set up the first icon: right-click > Properties > Target, edit in the necessary startup switch).

Once you know that works, right-click the shortcut > Copy, then right-click the desktop > Paste to set up the second icon. Then you can modify the Target of the second icon with the name of the other profile.

And then you can hide it from other people. ;-)

See:

• http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_windows
• http://kb.mozillazine.org/Shortcut_to_a_specific_profile
• http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox

You can add -no-remote to the command line to open another Firefox instance with its own profile and run multiple Firefox instances simultaneously.

• http://kb.mozillazine.org/Opening_a_new_instance_of_Firefox_with_another_profile

See also:

• https://developer.mozilla.org/Mozilla/Multiple_Firefox_Profiles

Hi Jscher2000,I have yet a small problem,as my Firefox was reseted to get rid-off viruses,as you know,it has lost its good feature:it used to underline incorrect English spelling with red line in forms.How to switch on this feature again? My English is not good enough to spell correctly :( Is it some addon that does this job? Can I switch off this feature for particular url's? Thank you,Max

Hi Max, usually Firefox only marks misspelling in multi-line form controls, and not in single-line form controls. If that is the problem, you can change the setting here:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste SPEL and pause while the list is filtered

(3) Double-click the layout.spellcheckDefault preference and change the value from 1 to 2:

0 = no marking 1 = mark misspellings in multi-line controls 2 = mark misspellings in single and multi-line controls

Firefox does not have a setting to change spelling by site, as far as I know. Sites can disable spell-checking for a form or for a field on a form. If you right-click the field, the checkmark will be missing before "Check Spelling" and you can try clicking it to turn it on, but that is only good until you reload the page.

If after the above Firefox still does not mark misspellings in English, is it possible that you had installed an additional dictionary before? To add a dictionary, please try right-clicking in the form control, then Languages, then Add Dictionaries.

Hi Jscher, Works fine. I've switched off spell checker by default and check it only if necessary.The dictionary wasn't installed.

Is it possible to force video (on youtube) in particular tab not to be run by default, after start of Firefox?If not,how to stop all videos at start up in about:config? I have some Physics and music videos which all get executed on startup. Thank you for your help,Max

Video autoplay depends on the player. For Flash, the "Ask to Activate" is on/off by server name. For HTML5 video, you can toggle this setting:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste media and pause while the list is filtered

(3) Double-click the media.autoplay.enabled preference to switch it from true to false

Note: on YouTube, the player likely will show a pause button and buffering, but Firefox 41 does not let the video start. To start it, click the pause button and it changes to play, then click the play button. Other sites may be similar, I haven't tested much with that setting.

Hi Jscher, do you please have a hint, where to set duration of the changed color of links already visited in html pages? At best, to unlimited time... Best, Max

Hi Max, visited link marking is based on your history. If a link is removed from history, Firefox doesn't know that it has been visited. History can't be kept forever, but Firefox usually keeps it for many, many months. If you need history forever, you could look for an add-on for that.

Hi Jscher I have a problem concerning Firefox's treating pdf files: I would like to color certain lines (by selecting with a mouse) in opened pdf within Firefox with red yellow or blue color. How this can be most easily achieved? Is there an addon for this? Perhaps at first I should save a copy of that pdf in a local file? Best, Max

Hi Max, I don't think Firefox's built-in PDF viewer will be very good for that because the text you see is part of an image. There is a transparent layer of text for searching which is superimposed over the background image, but I suspect it would be extremely ugly when colored, if that is even possible...

Hi Jscher,

this problem is almost not suited for this site, but as I don't know whom to ask, I'll try you: do you use Facebook?Since last week,I'm facing this problem: so far friends were displayed on the right hand side,without a possibility of closing this window.But suddenly the friends are displayed in a chat like window,which can be enlarged or dismissed by clicking on the top of it, and what's worse, it's wide and does not fit the whole height of the browser. How do I get back to the previous version,thin bar on the right hand side? Is this due to some mozilla's setting? Best, Max

Hi Max, I rarely use Facebook, so I couldn't tell you what is normal vs. what might be the effect of account differences or our respective add-ons and tweaks. If Facebook looks different in other browsers, then you could start a new question about why Firefox is different. (This thread is three pages long now and it's annoying working with long threads on this forum.)