how do I turn off Firefox welcome window?

Hi,

Please see this.

My homepage was not changed in options and my original homepage still opens normally. My problem is two separate windows opening.

http://www.mozilla.org/en-US/firefox/11.0/whatsnew/

Please also delete the sessionstore.* files in the Firefox Profile Folder after exiting Firefox. You can also open the profile folder from Firefox Help (Alt + H) > Troubleshooting Information > Open Containing Folder. If the problem persists please try to Reset toolbars and controls and Make Changes and Restart in the Firefox Safe Mode startup screen.

Firefox Profile Folder & Files

Do you mean that you get two tabs in the same window or two windows with each one tab?

Did you check for problems with the file(s) that store the preferences and delete or move the prefs.js file and possible user.js file?

• http://kb.mozillazine.org/Preferences_not_saved
• https://support.mozilla.org/kb/Preferences+are+not+saved

I get two tabs in the same window prefs.js file and user.js file are not write protected and are in place.

Did you give it a try to (re)move the prefs.js and user.js files to see if that helps?