The following method will not prevent the home page from being changed, but whenever you start Firefox, it will reset the home page back to the one that you want if it has been changed.

1. First you need to open the profile folder, for details of how to do that see the profiles article.
2. Close Firefox, and using a text editor create a file called user.js (this file may already exist)
3. Add the following line to user.js, using the home page that you want.

user_pref("browser.startup.homepage", "http://www.google.com/");

For more details on that file see http://kb.mozillazine.org/User.js_file

Note that if you want to change the home page then you need to make the change in user.js as well or your change gets lost on the next start of Firefox. You can do that by copying the corresponding line from prefs.js to user.js after you have closed Firefox.

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder

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

Thank you kindly, guys!

I created a user.js file and entered the line exactly as you showed (adding my preferred home page where appropriate). However there was already a line like that in the prefs.js file. Does "user.js" override "prefs.js"?

Thanks, again!

Oh, Now i get it! Done! - and thanks!

Yes. On each start of Firefox the file user.js is read after the file prefs.js and overrides corresponding settings in prefs.js.
If you close and restart Firefox then the current settings are saved in prefs.js and if you didn't make any changes then the lines in prefs.js and user.js are the same.

Thanks again, you guys ROCK!

Made the necessary changes to both prefs.js and user.js but to no avail. Homepage just keeps getting overridden by the same page. Simple question - why on earth is a Homepage hijack without the user's permission possible? Oh well, back to Explorer.

To which page is your home page changed?

Did you check for extensions that make such a change?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

• Don't make any changes on the Safe mode start window.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Now established that when my wife clicks on a link in her email client - Incredimail - Firefox goes straight to that page on subsequent openings until another link is clicked then that page in turn becomes the first page opened.

This doesn't happen with any other browser.

Default theme in use

Try:

• http://help.incredimail.com/incredimail/help_center/help_article.aspx?article_id=276&lang_id=9