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}

Hey, Fred McD

Thanks for the suggestions. I checked the (Windows) firewall--found Firefox listed as allowable, but alas, I cannot access any portion of Firefox. The Firewall is Windows, and Avira is mentioned in Enum. I could not find anything at Avira that seemed helpful.

Did you already reboot Windows? Seems cliché but in case there are problems with permissions, it helps.

Hey, jscher2000

Thanks for the suggestion. Reboot did not solve the problem.

Everyone: may I add--my laptop opens Firefox in Windows 8.1 OK.

Did you follow the instructions regarding the firewall? (removing Firefox)

Fred McD

I did to the best of my ability. See my post above.

In any event, I did not intentionally make any change to my Firewall settings.

Do you recall any changes around the time this problem started, such as a Windows update, or another application installed, etc.?

When you try to start Firefox, what happens? For example:

• Error message (what message?)
• Nothing seems to happen

If you check the Windows 10 Task Manager (Ctrl+Shift+Esc, "More Details"), Details tab, can you see any firefox.exe processes running in the background? How many processes?

If Firefox crashes early, there may be information in the Windows Event Viewer, Applications log.

jsher2000

When I try to start Firefox, nothing seems to happen. There is no trace of a Firefox process in the Task Manager listings.

I don't think Firefox crashes. It just refuses to open when I click on the desktop icon or from the Start Menu.

What if you go to the folder where Firefox is located. Usually it is one of these:

• C:\Program Files\Mozilla Firefox
• C:\Program Files (x86)\Mozilla Firefox

If you double-click firefox.exe here, will it run?

If not:

Right-click firefox.exe and click Rename, then add a 1 so it's firefox1.exe and then click away to save the change.

Will it run after renaming?

jscher2000

I renamed Firefox.exe as instructed. It appears that I have now installed a brand new version of Firefox. That's good...no, that's bad. What I now have is a version with none of my settings retained.

But how dare I be so ungrateful??!! Firefox is now working, and I'm glad to have it back. I can always get the settings back to my favorite configuration.

Thanks, jscher and Fred McD for your timely and competent support.

Merry Christmas to you guys!

Hi dougkeeling, if firefox1.exe will run but firefox.exe will not, that sometimes indicates a malware infection. Suggested cleaning tools are listed in this article: Troubleshoot Firefox issues caused by malware.

If your settings seem lost, could you try this:

Profile Manager Page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

Do you have another profile named default or default-longnumber listed on this page? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

If it isn't what you want, simply close that new window.

If it IS what you want, back on the about:profiles page, click the Set as default profile button for that profile so Firefox uses it automatically at the next startup.

Anything useful there?

Hey, jscher2000

Interesting, but useful only for my continuing education.

I found the second profile, but, alas, it (Profile:default) was clean as is the other (Profile:default-release), so I was not able to retrieve/resurrect my original settings.

I sincerely hope you can guide me back to that profile, as I am struggling to recreate the old familiar settings.

Do you have a folder named "Old Firefox Data" on your desktop? That is created when the Firefox Refresh feature was triggered, so you wouldn't normally find one, but it's worth a check.

Do you have any other Windows user profiles on your system? In other words:

C:\Users\some_other_name\

If so, you might turn on viewing of hidden files and folders and check for any Firefox profiles under that user.

https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

C:\Users\some_other_name\AppData\Roaming\Mozilla\Firefox\Profiles

Hey, jscher2000

I forgot to include in my last post: I have run Windows Defender, MalwareBytes, and Trend Micro Housecall searching for malware. All report no problems.

I could not find "Old Firefox Data" anywhere. I did find one "Firefox.exe" in my recycle bin, but I have sent several versions there since I started trying to solve this problem.

I also did not find any other profiles. But on one occasion, I manually removed every Firefox element(?) by hand. I found that in the Recycle Bin and searched them all for something with the word "Profile" in it to no avail.

Perhaps I should mention that the desktop icon for Firefox is not the familiar one. Don't know if that's significant.

dougkeeling said

But on one occasion, I manually removed every Firefox element(?) by hand. I found that in the Recycle Bin and searched them all for something with the word "Profile" in it to no avail.

Hmm, in your Recycle Bin, do you have or can you add the column "Original Location"? that would be the easiest way to sort down to the correct path and see whether you deleted the entire Firefox or Mozilla folder and that's why Profile is not listed.

Perhaps I should mention that the desktop icon for Firefox is not the familiar one. Don't know if that's significant.

How unfamiliar is it? There are variants of Firefox (beta, Developer Edition, Nightly) that have different icons.

Hey, jsher2000

Easy one first: the new Firefox icon is a sheet of paper with a dogear on the top right.

Now it's confession time: I have no idea how to "...add a column...". But it was my intention at the time, ill-advised or not, to delete the entire Firefox folder, as I had exhausted my ideas of how to restore Firefox. The intent was to start anew. I did mention that I had looked at every line item that I deleted and did not see anything relateable to "profile."

I tried to return all of those deleted items to my desktop, but got error messages "...need permission...", or something similar. Not knowing how to obtain "permission," I gave up.

What if you (carefully) rename the current Firefox folder to FirefoxNEW and then restore the deleted one back to its original location. Will Windows do that? Then rename that folder to FirefoxOLD and rename the FirefoxNEW folder back to Firefox. At least then you'll have folders to mine for valuable data.

Just to clarify, I mean the folder here:

C:\Users\username\AppData\Roaming\Mozilla\Firefox

And regarding --

dougkeeling said

Easy one first: the new Firefox icon is a sheet of paper with a dogear on the top right.

That's probably due to renaming firefox.exe to firefox1.exe ?

I haven't been able to rename the Firefox folder. I get the error message that I can't rename it because "...the folder or a file in it is open in another program." I am stumped, as I can't find any file/folder with Firefox in it open at this time.

In any event, to my chagrin, I now note that the old Firefox.exe that was in the Recycle Bin is no longer there. I don't know why--I definitely did not remove it deliberately.

As I work to reestablish my preferred settings, I see that I cannot copy and paste in the version (71.0, I think) of Firefox I currently have on my computer. Have I succeeded in corrupting this installation?