See these articles for some suggestions:

• https://support.mozilla.com/kb/Firefox+has+just+updated+tab+shows+each+time+you+start+Firefox
• https://support.mozilla.com/kb/How+to+set+the+home+page - Firefox supports multiple home pages separated by '|' symbols
• http://kb.mozillazine.org/Preferences_not_saved

I have done everything that you said to do in you reply. It did not fix the problem. I still get "Welcome to Firefox" tab. I get it if I set " Open to Blank Page". I get it and my home page if I set "Open to home Page".

I think that it trys to update Firefox every time I launch. How can I stop the automatic updating when I launch?

Did you delete the file prefs.js in the Firefox Profile Folder ?

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• Help > Troubleshooting Information > Profile Directory: Open Containing Folder

Yes. I still get the "Welcome to Firefox." tab

Looks that your current profile isn't working properly.

Create a new profile as a test to check if your current profile is causing the problems. See Basic Troubleshooting: Make a new profile:

• https://support.mozilla.com/kb/Basic+Troubleshooting#w_8-make-a-new-profile

If that new profile works then you can transfer some files from the old profile to that new profile (be careful not to copy corrupted files)

See:

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Following the steps in the links you sent solved the problem. Thanks.