That's very hard to explain!

Could you start by checking for your Firefox settings/data, this would be in your Firefox profile folder. (This is distinct from the program folder.)

Select and copy the following, then paste it into the Start menu search box and press Enter to load it:

%APPDATA%\Mozilla\Firefox\Profiles

If that folder exists (fingers crossed!) you may see one semi-randomly named folder, or more than one. Check inside the most recently modified folder for a folder named bookmarkbackups and it should contain files with long names including the date, for example:

bookmarks-2015-10-15_5555_OXQasdf03y8WgCS4wYnWVA==.jsonlz4

Please make a backup of this folder in a safe location such as your documents folder, in case there are further issues with Firefox.

And then install Firefox again as follows:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 41.0.1 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.)

(B) Exit out of Firefox (if applicable).

(C) Rename the current program folder -- assuming it exists -- either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\OldFirefox

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\OldFirefox

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

Can you delete search history entries and have them stay deleted?

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

• \OldFirefox\Plugins
• \OldFirefox\browser\plugins

Otherwise, there's no reason to keep the old folder except research/curiosity.

Thank you for your simple instructions ... they are easy to follow. However ... When I click on download IE says the page can't be displayed and to turn on T 110 and some other ones in advanced settings. I went in the settings and all of them are already on! So IE won't let me download firefox! I have the last copy of firefox 41.0.1 on my desktop 10 01 2015 .... should I try to use it? Also while poking around I found this file in this location: p......./appdata/roaming/mozilla/firefox/profiles/hjy....default/crashes/store.json.mozlz4 dated 10 15 2015 would it be helpful since it was created last night. Do I use the add images below to send it???? thank you ..... I also found maintenance logs from late last night and early this morning??? While finding firefox folders to rename.

Hi pricer, go ahead and try the installer you downloaded before to see whether it works. If it's the "stub" installer it will need to connect back to Mozilla's servers for additional files. Hopefully that will work.

I don't understand the error message from IE. Inability to download can be a sign of a malware problem on your system. You could try some of the free cleaning tools in our support article: Troubleshoot Firefox issues caused by malware.

Also while poking around I found this file in this location: p......./appdata/roaming/mozilla/firefox/profiles/hjy....default/crashes/store.json.mozlz4 dated 10 15 2015 would it be helpful since it was created last night. Do I use the add images below to send it???? thank you .....
I also found maintenance logs from late last night and early this morning??? While finding firefox folders to rename.

You don't need to search for folders to rename. You only would need to rename the one program folder I mentioned.

The crashes might be interesting, but I believe that file is compressed (the lz4 ending) and probably unreadable. To find crash report IDs for crashes submitted to Mozilla, you can use the steps in the following article: "Firefox crashes - asking for support" (the method for finding them on disk instead of using the about:crashes page).

Thank you so much, I have my firefox back and a smile on my face!