First, run these programs to clean out your system;

You may have ad/mal-ware. Further information can be found in this article; https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

After running the scanners above, and your antivirus;

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 ++++++++++++++++++++++++++++ Look for, and remove any Mozilla or Firefox program folders. Do not remove the Mozilla Thunderbird folder if there is one.

Do Not remove the profiles folder.

After rebooting the computer, run a registry scanner if you have one. Then run the installer. +++++++++++++++++++++++++++ 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

Thank you Fred for your response. The article regarding virus scanners was helpful, I ran all the scanners and no issues found. After I uninstalled Mozilla ver 58.0.1; ver 58.0 still appears in the Apps/Features; I get this error message "Windows can not find: "C:\Program Files (x86)\Mozilla Firefox \unistall\helper.exe" . As I indicated, McAfee thought this file was a virus and quarantined it, I tried restoring didn't appear to help. I deleted all of the Mozilla Firefox folders in file explorer. I suspect that the registry may have gotten corrupted. There are 93 registry entrees when I scearched on "Mozilla", I am hesitant to delete them since I don't know if this will create other issues.

Maybe it is just an orphaned entry that was leftover in the Windows Registry and the files no longer are present on the hard drive. We regularly see this reported that the updater didn't remove the entry of the previous version. You can manually remove the entry yourself or use a registry cleaner.

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\

I think it is an orphaned entry, tried to clean out the registry entry but having some difficultycor-el said

Maybe it is just an orphaned entry that was leftover in the Windows Registry and the files no longer are present on the hard drive. We regularly see this reported that the updater didn't remove the entry of the previous version. You can manually remove the entry yourself or use a registry cleaner.

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\

I agree likely orphans; I deleted those entries in the registry, will reboot and see if any changes. Thanks

It is okay to remove any entries in the registry when you are re-installing a program. This would help remove any bad or unwanted listings. And the installer will put in the new registry entries.