hi, that's unusual. next to the security software already in place, can you please run a scan with various other security tools like the free version of malwarebytes, adwcleaner & eset online one-time scanner and see if they come up with some stuff?

almost 10 days and still same issue and i need mozilla urgently

Let’s do a full clean re-install; Download Firefox For All languages And Systems {web link}

Save the file. Then Close Firefox.

Using your file browser, open the Programs Folder on your computer.

Windows: C:\Program Files C:\Program Files (x86)

Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it. See Install Firefox on Linux; https://support.mozilla.org/en-US/kb/install-firefox-linux

If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory. http://www.mozilla.org/firefox#desktop ++++++++++++++++++++++++++++ Do Not remove the profiles folder.

Look for, and rename any Mozilla or Firefox program folders by adding .old to them. Do not rename the Mozilla Thunderbird folder if there is one.

After rebooting the computer, run a registry scanner if you have one. Then run the installer. If all goes well, remove the OLD folders when you are done. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again.

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia

FredMcD said

Let’s do a full clean re-install; Download Firefox For All languages And Systems {web link} Save the file. Then Close Firefox. Using your file browser, open the Programs Folder on your computer. Windows: C:\Program Files C:\Program Files (x86) Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it. See Install Firefox on Linux; https://support.mozilla.org/en-US/kb/install-firefox-linux If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory. http://www.mozilla.org/firefox#desktop ++++++++++++++++++++++++++++ Do Not remove the profiles folder. Look for, and rename any Mozilla or Firefox program folders by adding .old to them. Do not rename the Mozilla Thunderbird folder if there is one. After rebooting the computer, run a registry scanner if you have one. Then run the installer. If all goes well, remove the OLD folders when you are done. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again. http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia

Let me see if I got you correctly before I judge your respond since I am not so tech savy. I have uninstalled firefox, then removed traces of it, from register and Program 86x, then reinstalled firefox. If that is what you are trying to say, it has not worked at all!

I have run a system resort point before the problem occurred and reinstalled firefox (version 36 - the one I like) Now I am getting a new error message as follow The program can't start because "mozglue.dll" is missing from your computer. Try reinstalling the program to fix this problem.

You need to do a full install because that file is missing.

https://support.mozilla.org/en-US/kb/install-older-version-of-firefox?cache=no Be sure to read everything here.

If you still want to downgrade, look under; I still want to downgrade. Click the Directory of other versions and languages link. Look for the directory of the version that you want. But, remember that old versions may have security issues.

You should also check out Firefox; Extended Support Release https://www.mozilla.org/en-US/firefox/organizations/

https://www.mozilla.org/en-US/firefox/organizations/notes/

https://www.mozilla.org/en-US/firefox/organizations/system-requirements/

I have manually installed the missing dll file and now I have a new error message "couldn't load XPCOM"

FredMcD said

You need to do a full install because that file is missing.

I reinstalled it but it is not working out.

Did you do a full clean reinstall? see https://support.mozilla.org/en-US/questions/1164273#answer-980585

FredMcD said

Did you do a full clean reinstall? see https://support.mozilla.org/en-US/questions/1164273#answer-980585

Yes I did, and got the error msg.

a new error message "couldn't load XPCOM"

The full installer should have installed all of the needed files.

I called for more help.

No It did not install all the needed files and as a result the error message is now "couldn't load XPCOM"

Did you delete the Firefox program folder before reinstalling Firefox?

You can also try to install Firefox in Windows Safe Mode.

Yes I did delete it before reinstall.

I tried but still same problem.

And Windows Safe Mode?

Nope it did not work out.

Since you run version 36 and looking at this question, what happens when you install version 36.0.1 if not using it already?

Additionally I’d think of running a System File Check (sfc.exe) as suggested there.

I installed 36.0.1 and Firefox is working on my laptop now. Thanks!