Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox will not start after update or reinstall. Does not start. Does not start. Does not start.

  • 5 replies
  • 2 have this problem
  • 6 views
  • Last reply by FredMcD

more options

Last week, Firefox performed an automatic update and restarted itself. Now it never starts. I can see firefox.exe processes running, but no window is ever visible.

Things I have tried:

  • uninstalling and reinstalling Firefox using latest installer.
  • while Firefox is uninstalled,
    • delete C:\Program Files\Mozilla\* and C:\Program Files (x86)\Mozilla\*
    • delete anything under C:\Users\<me>\AppData\ that had "Mozilla" in the name
  • tried using Profile thingy (mozilla.exe -P) -- a firefox.exe process was running, but no window ever opened.

This is on a company-owned laptop running Windows 7 x64 and kept up-to-date. Mozilla ran without complaint until last week's automatic self-update.

PLEASE DO NOT SUGGEST ANY STEPS THAT REQUIRE AN OPEN FIREFOX WINDOW. THAT JUST TELLS ME THAT YOU HAVEN'T ACTUALLY READ THIS.

Last week, Firefox performed an automatic update and restarted itself. Now it never starts. I can see firefox.exe processes running, but no window is ever visible. Things I have tried: * uninstalling and reinstalling Firefox using latest installer. * while Firefox is uninstalled, ** delete C:\Program Files\Mozilla\* and C:\Program Files (x86)\Mozilla\* ** delete anything under C:\Users\<me>\AppData\ that had "Mozilla" in the name * tried using Profile thingy (mozilla.exe -P) -- a firefox.exe process was running, but no window ever opened. This is on a company-owned laptop running Windows 7 x64 and kept up-to-date. Mozilla ran without complaint until last week's automatic self-update. PLEASE DO NOT SUGGEST ANY STEPS THAT REQUIRE AN OPEN FIREFOX WINDOW. THAT JUST TELLS ME THAT YOU HAVEN'T ACTUALLY READ THIS.

All Replies (5)

more options

Some problems occur when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

  • Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
  • Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

more options

Firewall, antivirus, etc. are managed by the domain. It is not possible to determine which product they use, just that I can't rule out Windows Firewall. Whatever it is, I am probably running the latest version of it. The link to the EnumProcess utility in that article no longer works (times out).

I went into Win7 control panel: Control Panel -> System and Security -> Windows Firewall -> Allowed Programs. I cannot change the settings here, because they're controlled by the domain, but I can see every program/feature that it is currently configured for. "Firefox," "Mozilla," or "Mozilla Firefox" do not appear anywhere in that list.

more options

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

more options

This does not work. Same behavior as before: firefox.exe process launches and stops working. The "Safe Mode" window is never shown.

more options

Start your Computer in safe mode with network support. Then start Firefox. Try Safe websites. Is the problem still there?

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode Starting Any Computer In Safe Mode; Free Online Encyclopedia