You can check for recently installed suspicious or unknown extensions.

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

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

hello SummerBreeze, you may have malicious addons present. please perform all these steps:

1. reset firefox (this will keep your bookmarks and passwords)
2. afterwards go to the firefox menu > addons > extensions and in case there are still extensions listed there, disable them.
3. finally run a full scan of your system with different security tools like the free version of malwarebytes and adwcleaner to make sure that adware isn't present in other places of your system as well.

Troubleshoot Firefox issues caused by malware

I defaulted Firefox, (disabled add ons, (which were only Norton) then went to Malwarebytes. As I scrolled down their page, random words were highlighted, and true to form, ads for vehicles morphed into larger windows asking me to click to update my security! I scrambled out, noticing on one of the url bars this (api.jollywallet.com) which sure looked suspicious. Did the Malwarebytes, re-enabled Norton, checked one web site I go to, no blue highlights, went to another, blue highlights. Sigh. We have Norton, Ad-Ware Anti-virus, Spy-bot and Malwarebytes. This thing still persists. I'm just learning to avoid all blue lettering. Thank you for trying........

Hubby and I have been working on this all day, kinda tired, but there's tomorrow, fresh day, and I may just start down the line and see what it takes. Thanks to you all!

Sorry to be so persistent, but had another one of those windows come up, and Norton caught it, said it was from Fake App Attack, Fake Browser Update 2, with a high risk. Norton said no action was required. Sigh......

Aha! During the past few days, I have learned more on this computer.... Kim Komando suggested a program called "Should I remove it?" I checked on this, and the program showed a high risk program called pasta quotes that inserts ads into various web sites and uses high lite words to redirect you elsewhere. I used Should I Remove It and uninstalled pastaquotes. So far, it looks like the problem is solved. Thank you all for your support! Got me motivated!