Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

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 won't start, even after fresh re-install. How to mitigate that?

  • 3 respostas
  • 1 has this problem
  • 1 view
  • Last reply by FredMcD

more options

On my company Win 10 machine, I had Firefox working as a secondary browser (normally using Chrome). Recently I tried starting Firefox and it won't start. For the last two days I am trying all the methods I found to fix the problem. The symptom is after clicking on the icon, a process is created but the Firefox application it self does not run.

I tried the following:

1. Run in safe mode

2. Uninstall and re-install the application, trying both 64-bit and 32-bit installs of version 59.0.2.

3. Install w/o the maintenance module option

4. Uninstall, then clean up Firefox and Mozilla related folders under AppData and Program Files, and re-install

5. Trying on my home network and office network, both directly and through VPN.

6. Combinations of the above, and of course, killing the firefox.exe process in between attempts.

Nothing helps. All I see is the process but not the application.

Machine is Windows 10 64-bit. Other browsers used are Chrome and IE11.

How can I debug this situation?

On my company Win 10 machine, I had Firefox working as a secondary browser (normally using Chrome). Recently I tried starting Firefox and it won't start. For the last two days I am trying all the methods I found to fix the problem. The symptom is after clicking on the icon, a process is created but the Firefox application it self does not run. I tried the following: 1. Run in safe mode 2. Uninstall and re-install the application, trying both 64-bit and 32-bit installs of version 59.0.2. 3. Install w/o the maintenance module option 4. Uninstall, then clean up Firefox and Mozilla related folders under AppData and Program Files, and re-install 5. Trying on my home network and office network, both directly and through VPN. 6. Combinations of the above, and of course, killing the firefox.exe process in between attempts. Nothing helps. All I see is the process but not the application. Machine is Windows 10 64-bit. Other browsers used are Chrome and IE11. How can I debug this situation?

ysap modificouno o

All Replies (3)

more options

Hi, you can try this : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

Reinstall with Current Release Firefox 59.0.2 with a Full Version Installer

Please let us know if this solved your issue or if need further assistance.

more options

Thanks, Pkshadow. I believe that all the suggestions you provided were tried and are reported in me original post.

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}