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

BTW; Your System Details shows;

Installed Plug-ins

Shockwave Flash 14.0 r0 Shockwave Flash 11.5 r502

Having more than one version of a program may cause issues.

Go to the Mozilla Add-ons Web Page {web link} (There’s a lot of good stuff here) and search for a good add blocker.

maxsmum,

Please provide a list of your installed extensions. Type about:support in the URL bar and hit Enter. Hit the Copy text to Clipboard button, then Paste that info to the Post a Reply box in this thread.

I suspect that you have an add-on named something like SaltarSmart installed in your Firefox, which might be the cause of those tabs / windows.