If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block content (Adblock Plus, NoScript, DuckDuckGo PE, Disconnect, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block content.

• make sure your extensions and filters are updated to the latest version
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Firefox shows a purple shield instead of a gray shield at the left end of the location/address bar in case Enhanced Tracking Protection is blocking content. You can click the shield icon for more detail and possibly disable the protection. You can check the Web Console for relevant-looking messages about blocked content.

• https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop
• https://support.mozilla.org/en-US/kb/smartblock-enhanced-tracking-protection
• https://support.mozilla.org/en-US/kb/trackers-and-scripts-firefox-blocks-enhanced-track

You can try these steps in case of issues with webpages:

You can reload webpage(s) and bypass the cache to refresh possibly outdated or corrupted files.

• hold down the Shift key and left-click the Reload button
• press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• press "Command + Shift + R" (Mac)

Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Settings).

"Remove the Cookies" for websites that cause problems:

• Settings -> Privacy & Security
  Cookies and Site Data: "Manage Data"

"Clear the Cache":

• Settings -> Privacy & Security
  Cookies and Site Data -> Clear Data -> [X] Cached Web Content -> Clear

• https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox
• https://support.mozilla.org/en-US/kb/how-clear-firefox-cache

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

• https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop
• https://support.mozilla.org/en-US/kb/smartblock-enhanced-tracking-protection
• https://support.mozilla.org/en-US/kb/trackers-and-scripts-firefox-blocks-enhanced-track

The ideas above were useful but I finally solved the problem by google searching for "purge firefox." I found a site that helped. I deleted registry entries with regedit. I ran Ccleaner several times, each time it found more registry items that I deleted (only firefox items). One of those was blocking my Amazon purchases. It took about an hour of searching and deleting but I got it out.

However, when I clicked the firefox installer, it continued to recognize that I had used firefox in the past. Even after all I did. So Firefox should have a way of deleting everything, a total purge, without us having to go through regedit etc.

Second, when I clicked the firefox installer it had a little message with a box, checked. I may have UNchecked that box. It is not clearly stated what that little box means. I wanted a "clean install," purge everything and reinstall. I did NOT unclick that box or whatever (I cannot get it back).

Mine was an obscure problem to be sure. I don't know how it happened but there was a Windows update a few days before, and my Outlook also went bonkers. Somehow it wrote a Rule to itself, so wierd.

I am happier now. No need to use Edge.

That was very good work. Well Done. Please flag your last post as Solved Problem as this can help others with similar problems. Go to that post and click the 'Solved' button to its right.

However, when I clicked the firefox installer, it continued to recognize that I had used firefox in the past.

Note: Firefox comes in three or more folders on all computers. They are;

Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And two folders in the profile of each user on the computer for each Firefox profile for that user.

If you remove the Firefox program folder, the user profiles would not be affected.

Use these links to create a new profile. Use this new profile as is. Is the problem still there?

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Type about:profiles<enter> in the address box.

I wish I had known where the Firefox folders were located when I started to reinstall the program. Every time I reinstalled, I got a message that I could use my old data; frustrating!

Give some Uninstall completely instructions.

I mentioned that the message mentioned above is too vague.

You guys could do better. Too much attention on adding more features.

You guys could do better. Too much attention on adding more features.

I agree. On that and other things.

The people who answer questions here, for the most part, are other users volunteering their time (like me), not Mozilla employees or developers. If you want to leave feedback for Firefox developers, you can go to the Firefox Help menu and select Submit Feedback.... Alternatively, you can use this link. Your feedback gets collected by a team of people who read it and gather data about the most common issues.

You can also file a bug report or feature request. See File a bug report or feature request for Mozilla products for details.