When my computer boot even if i have not open firefox there is a firefox process using 50% of my cpu

When windows 10 start, all my start up programs start an then without doing anything appear a firefox process using 50% of my cpu, firefox doesnt open and i can open firefox and it show me no message. i have to close it manually with the task manager and while my computer is still on it wont happen again but right after i restart it will happen again. i have tried almost everything here https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-or-cpu-resources but nothing seems to work, help pls