Hello, Other users who have reported having this problem have fixed it by: * Updating Java (doesn't look applicable to you) * Scanning for malware Users who have fixed it found this scanner particularly useful * [http://general-changelog-team.fr/en/downloads/viewdownload/20-outils-de-xplode/2-adwcleaner AdwCleaner] (for more info, see this [http://www.bleepingcomputer.com/download/adwcleaner/ alternate AdwCleaner download page]) However, it might be safer to scan with at least one scanner as they each have different methods of detection: * [http://www.malwarebytes.org/products/malwarebytes_free/ MalwareBytes' Anti-Malware] * [http://www.microsoft.com/security/scanner/default.aspx Microsoft Safety Scanner] * [http://support.kaspersky.com/viruses/disinfection/5350 Anti-Rootkit Utility - TDSSKiller] * [http://www.surfright.nl/en/hitmanpro/ Hitman Pro] * [http://www.eset.com/us/online-scanner/ ESET Online Scanner] ---------- If the above do not help at all, can you try running Windows Safe Mode with network support (press F8 on the boot screen) as a test to see whether some other application (such as an antivirus) might be interfering with Firefox? * http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/