Often this is due to a security block, either in your firewall software or other software that controls which programs can access the internet. Do these articles help? * [[Firefox can't load websites but other browsers can]] * [[Configure firewalls so that Firefox can access the Internet]]

Did you post this from another computer running Windows XP or are you running Firefox in compatibility mode on a Windows 7 computer? ----- Do a malware check with some malware scanning programs on the Windows computer.<br> Please scan with all programs because each program detects different malware.<br> 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:<br>http://www.malwarebytes.org/mbam.php *SuperAntispyware:<br>http://www.superantispyware.com/ *Microsoft Safety Scanner:<br>http://www.microsoft.com/security/scanner/en-us/default.aspx *Windows Defender: Home Page:<br>http://www.microsoft.com/windows/products/winfamily/defender/default.mspx *Spybot Search & Destroy:<br>http://www.safer-networking.org/en/index.html *AdwCleaner:<br>http://www.bleepingcomputer.com/download/adwcleaner/<br>http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml *Kasperky Free Security Scan:<br>http://www.kaspersky.com/security-scan You can also do a check for a rootkit infection with TDSSKiller. *Anti-rootkit utility TDSSKiller:<br>http://support.kaspersky.com/5350?el=88446 See also: *"Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

Thanks but full disable of firewall didn't help.

Yes, the question was poster from my desktop machine which is set to dual boot both windows 7 and Xp. I regularly run spybot scans but I'll try all the others you mentioned. Thanks