Please explain the problem in detail. What happens? What is/are the exact error message(s) ? Is the Firefox icon visible on the computer's taskbar? [https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode Start Firefox using Troubleshoot(Safe) Mode] {web link} A small dialog should appear. Click '''Start In Troubleshoot(Safe) Mode''' (not Refresh). Is the problem still there?