This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

opcom.dll - firefox won't connect to internet and says opcom.dll is missing.

  • 4 replies
  • 1 has this problem
  • 9 views
  • Paskiausią atsakymą parašė StephenRoss

more options

Firefox loads, but cannot connect to the internet. An error said opcom.dll was missing. But it is in two places on my computer. IE and Chrome also will not connect to the internet. The problem is not on this computer. I am using a different computer to connect and ask for help.

Firefox loads, but cannot connect to the internet. An error said opcom.dll was missing. But it is in two places on my computer. IE and Chrome also will not connect to the internet. The problem is not on this computer. I am using a different computer to connect and ask for help.

All Replies (4)

more options

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:

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.

Modified by kobe

more options

Please update to the current Firefox 22.0 release.

  • Help > About 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.
more options

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.

more options

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.