Create a new profile as a test to check if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Do a clean reinstall and delete the Firefox program folder before (re)installing a fresh copy of the current Firefox release.

• Download the Firefox installer and save the file to the desktop
  https://www.mozilla.org/en-US/firefox/all/

If possible uninstall your current Firefox version to cleanup the Windows registry and settings in security software.

• Do NOT remove "personal data" when you uninstall your current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including data in profiles created by other Firefox versions.

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• (32 bit Windows) "C:\Program Files\Mozilla Firefox\"
• (64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"

• It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
• http://kb.mozillazine.org/Uninstalling_Firefox

Your bookmarks and other personal data are stored in the Firefox profile folder and won't be affected by an uninstall and (re)install, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_reinstall

Do a malware check with several malware scanning programs on the Windows computer. Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• AdwCleaner:
  http://www.bleepingcomputer.com/download/adwcleaner/
  http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender:
  http://windows.microsoft.com/en-us/windows/using-defender
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• Anti-rootkit utility TDSSKiller:
  http://support.kaspersky.com/5350?el=88446

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked
• https://support.mozilla.org/kb/troubleshoot-firefox-issues-caused-malware

I previously tried all of the above plus a lot more recommended methods to keep it from freezing when typing. It might freeze after 2 characters, maybe after 200 characters, but all of a sudden I cant type and it locks up. After maybe 15 seconds to a minute it releases and it's OK till the next time it freezes. Every other browser (and all other software) works fine, this is not a keyboard or driver issue. I have used Firefox since it's inception. I have used it on this PC for years before this occurred. I am totally bewildered.

its, hick. You can't spell can't either.

How does its memory usage look?

RAM Chrome using 150000K IE using 145000K Firefox using 210000K with no extensions enabled The above reading were taken at the same website for all 3 browsers

Essiar, good luck getting this problem solved! I know your pain! ;)

I have been having the same problem since January 2015. I have spent more time trying to fix this issue than one can possibly believe. I have, by process of (slow) elimination proven it not to be many things.

Now that I'm about out of things to try, I am investigating the problem being due to low resources because of Firefox (40 now). After a fresh cold reboot, I can type like a maniac and have no problems. But after 30+ minutes, everything slows down and the typing buffer will not accept any more input. If I am patient enough to wait more than 3 or 4 minutes, whatever I had typed that did not show up, shows up. I am nearly insane with trying to fix this. I almost hate the computer now. LOL

So, frequent, cold reboots is the method of the day for me that works. Still need to find the REAL problem and fix it. Any help, anyone?

Firefox 40 on Win 8.1, HP computer (it sucks), 16 gigs RAM

Kathy