Firefox has no built-in option for blocking sites.

A few options for you.

1. Install the FoxFilter add-on, the downside is add-ons are fairly easy to circumvent - https://addons.mozilla.org/firefox/addon/foxfilter/
2. Another add-on that can filter content is the ProCon Latte Content Filter - https://addons.mozilla.org/firefox/addon/procon-latte/
3. Install a 3rd-party parental control program such as the free K9 web protection - http://www.k9webprotection.com/
4. Use the OpenDNS service, there is a free version, and with it you can filter content based on categories that you choose - http://www.opendns.com/

Firefox doesn't have that ability, but you can use this free app: http://www1.k9webprotection.com/

Incidentally, you need to update a couple of plugins. The versions you have installed at the moment expose your system to attack.

• Update Adobe Flash via http://get.adobe.com/flashplayer/
• Update VLC Player via http://www.videolan.org/

Here's the relevant Adobe security advisory: http://www.adobe.com/support/security/advisories/apsa11-02.html

As regards the VLC player, you currently have version 1.1.5 installed which is insecure. The link I've given you to v1.1.9 is also an insecure version, but better than the one you have at the moment. Just keep an eye on their site for when they release the next patch.

For more info, see VLC Player 1.1.9 closes security holes and A new security flaw hits VLC

Thank you.. <https://addons.mozilla.org/firefox/addon/foxfilter> works perfectly

The Foxfilter can be bypassed very easily simply by restarting Firefox in Safe Mode.

In Firefox 4 you can easily start Firefox in Safe mode by holding down the Shift key while double clicking the desktop shortcut, so you even do not need to go to the start menu of use the command line.

why is firefox allowing porn pop-ups and why do i need to download plug ins to prevent this ? just get it off my computer!! I have small Grandchildren ages 2 & 4 that play games on pbs.com also sesame street.I would appreciate for this to be taken care of immediately.

Your computer may be infected with malware if you get such unrequested pages opening.

Do a malware check with some malware scanning programs.
You need to scan with all programs because each program detects different malware.
Make sure that you update each program to get the latest version of their databases before doing a scan.

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy
• http://www.lavasoft.com/products/ad_aware_free.php - Ad-Aware Free

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked