hello JoRose, please refer to the following article which holds the most common solutions for the issue as you've described it: How to fix preferences that won't save

Thank you, I reset it, lets see if that works.

Which security software (firewall, anti-virus) do you have?

Does this only happen after you have rebooted the computer?

I have norton. It happened after I got that stupid malware browser thing.. ever since it hasn't worked properly. and I got rid of the malware.

Do a clean reinstall and delete the Firefox program folder before (re)installing a fresh copy of the current Firefox release.

Download a fresh Firefox copy and save the file to the desktop.

• Firefox 26: http://www.mozilla.org/en-US/firefox/all.html

if possible uninstall your current Firefox version to cleanup the Windows registry and settings in security software.

• Do NOT remove personal data when you uninstall your current Firefox version, because all profile folders will be removed and you lose personal data like bookmarks and passwords from profiles of other Firefox versions.

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• (32 bit Windows) "C:\Program Files\Mozilla Firefox\"
• (64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"

• It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
• http://kb.mozillazine.org/Uninstalling_Firefox

Your bookmarks and other personal data are stored in the Firefox profile folder and won't be affected by an uninstall and (re)install, but make sure that "remove personal data" is NOT selected when you uninstall Firefox.

If you keep having problems then also create a new profile.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_reinstall