Check your settings to see if it's not set to save sessions to reopen them again.

amiaelana said

When I open Firefox I get 10 tabs at the top, many are duplicates. I want to have control over my own tabs and not have 6 same tabs for one site and 4 for another.

Hello amiaelana,

Your system details show that you have this add-on installed :

Search Encrypt - A Private Search Engine 3.1.0

Would you please disable it and see if that will solve your problem  ?

See the third review :

https://addons.mozilla.org/en-US/firefox/addon/search-encrypt/reviews/

You can check for problems with the sessionstore.jsonlz4 file in the Firefox profile folder that stores session data.

• delete sessionstore.jsonlz4 and sessionstore.js

When sessionstore.jsonlz4 is deleted you lose pinned tabs and open tabs and you will have to recreate them, so if necessary make a note or bookmark them.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

See also:

• https://support.mozilla.org/en-US/kb/wrong-home-page-opens-when-i-start-firefox-how-fix