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firefox can't find xpcom.dll. The file is on the firefox directory but I still get the error message

Posted

firefox says it can't find xpcom_core.dll. The file is all three directories, i.e., firefox, thunderbird, and sundial. The error occurs multiple times in a row.

This happened

Every time Firefox opened

== as soon as 3.6.3 was installed

Chosen solution

The file xpcom_core.dll was last used in Firefox 2.0.0.x versions and is no longer present and used in current Firefox versions.
You seem to have a program or an add-on that is still looking for that file.
You will have to uninstall that program.


See Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems
See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Read this answer in context 0

Additional System Details

Installed Plug-ins

  • -Haptek Netscape Plugin module
  • Allows browsing on RealArcade sites with Mozilla browsers.
  • npunagi2
  • NPCpnMgr
  • Macromedia Shockwave for Director Netscape plug-in, version 10.1
  • McAfee Clinic Activator Plugin (1,0,0,5)
  • Mozilla ActiveX control and plugin module
  • COL Plugin
  • Coupons, Inc. Coupon Printer DLL
  • getplusplusadobe16236
  • NPRuntime Script Plug-in Library for Java(TM) Deploy
  • Default Plug-in
  • Adobe PDF Plug-In For Firefox and Netscape 8.2.2
  • 6.0.12.732
  • RealPlayer(tm) LiveConnect-Enabled Plug-In
  • RealJukebox Netscape Plugin
  • GEPlugin
  • Google Update
  • Shockwave Flash 10.0 r45
  • Windows Presentation Foundation (WPF) plug-in for Mozilla browsers
  • Google Updater pluginhttp://pack.google.com/
  • RealPlayer(tm) HTML5VideoShim Plug-In
  • Java(TM) Platform SE binary
  • Next Generation Java Plug-in 1.6.0_17 for Mozilla browsers
  • Npdsplay dll
  • DRM Store Netscape Plugin
  • DRM Netscape Network Object

Application

  • User Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 GTB7.1 (.NET CLR 3.5.30729)

More Information

---------------------------
firefox.exe - Unable To Locate Component
---------------------------
This application has failed to start because xpcom_core.dll was not found. Re-installing the application may fix this problem.
---------------------------
OK
---------------------------

cor-el
  • Top 10 Contributor
  • Moderator
10779 solutions 97010 answers

Chosen Solution

The file xpcom_core.dll was last used in Firefox 2.0.0.x versions and is no longer present and used in current Firefox versions.
You seem to have a program or an add-on that is still looking for that file.
You will have to uninstall that program.


See Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems
See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Modified by cor-el

ScPat 0 solutions 1 answers

I have the problem, even in safe mode, so it does not seem to be related to an extension or plugin. This error first appeared with the most recent update to Firefox.

bhargin 1 solutions 2 answers

Helpful Reply

I Googled xpcom_core.dll, resulting in the following link ... http://www.dll-error-fixes.com/fix-xpcomcoredll-error/ ), which indicated that this DLL is a Firefox plug in, and that it's apparently a Firefox-only problem. I found the file npmozax.dll file in the C:\Program Files\Mozilla Firefox\plugins\ directory, deleted it, and my "can't find xpcom_core.dll" problem appears to be gone in less than 5 minutes!

cor-el
  • Top 10 Contributor
  • Moderator
10779 solutions 97010 answers

FYI: In Firefox 3.6 and older versions only extensions are disabled if you start in Troubleshoot Firefox issues using Safe Mode, so it can still be a plugin problem.

I've also seen references that the Mozilla ActiveX plugin is connected with that issue.
The plugins list of the original poster shows that plugin.

The Mozilla ActiveX plugin is not compatible with Firefox 2 and 3 and you should remove it.

For instructions on how to remove the Mozilla ActiveX plugin see: http://kb.mozillazine.org/ActiveX

Modified by cor-el

skeuri 0 solutions 1 answers

Helpful Reply

I had this problem too. But was able to fix it.

It seems that the xpcom.dll file in the Firefox program directory had become corrupted. I couldn't remove it, even after an uninstall.

After the uninstall the Program Files/Mozilla Firefox directory was still present containing the corrupt .dll.

Without renaming the corrupt directort a new install will just go into the old corrput directory and the .dll will remain corrupt...

I just renamed the directory to something like Program Files/Corrupt Mozilla Firefox and reinstalled Firefox in a different new directory.... problem solved.

Hope this helps you too.

Modified by skeuri