Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• MalwareBytes' Anti-Malware
• TDSSKiller - AntiRootkit Utility
• Spybot Search and Destory

NOTE: Put the install files on a USB and run them on the infected computer.

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if your current antivirus let this through.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back to us! ________________________________________________________________________________

You can also try and see if firefox works in Windows Safe Mode With Networking if it does run the antimalware above. _________________________________________________________________________________

This could also be a system problem which could be resolved by running sfc /scannow in windows safe mode with networking.

Please update to the current Firefox 22.0 release.

• Help > About Firefox

• https://support.mozilla.org/kb/update-firefox-latest-version.
• https://support.mozilla.org/kb/Updating+Firefox

The Firefox 14 version that you currently run is no longer supported with security updates.

• It is important to update Firefox and add-ons to the latest version to get all security fixes.

Thanks very much. I'll update the other computer. This one is current and still gives me the error message about opcom.dll but loads anyway. Go figure.

Thanks very much. Firefox semi-fixed itself. I still get the error message, must click OK, but it loads anyway and seems to work fine. Thanks again.