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How do I re-install Firefox when I get "Couldn't load XPCOM" when I run the install?

  • 2 replies
  • 2 have this problem
  • 448 views
  • Last reply by cor-el

jomacny
jomacny

When I tried to open Firefox this a.m., I got 2 messages: 1) The procedure entry point could not be located in the dynamic library C:\Program Files (x86)\Mozilla Firefox\xul.dll . When I clicked OK I got 2) Couldn't locate XPCOM. Looked for a solution and it was suggested to uninstall and then reinstall. I did 2x. Never really got a finished message on the reinstall but got Couldn't locate XPCOM. Firefox shows up again in my program files after I try to install, but still doesn't work. Don't know how to fix and I want to continue using Firefox and not other browsers. I guess the question is what do I do now when I still can't get Firefox to work? Please note that I need easily understandable response as I'm not very technologically savvy.

I'm running Windows 10 on my desktop. The problem occurred when I tried to open Firefox this morning.

Thanks

When I tried to open Firefox this a.m., I got 2 messages: 1) The procedure entry point could not be located in the dynamic library C:\Program Files (x86)\Mozilla Firefox\xul.dll . When I clicked OK I got 2) Couldn't locate XPCOM. Looked for a solution and it was suggested to uninstall and then reinstall. I did 2x. Never really got a finished message on the reinstall but got Couldn't locate XPCOM. Firefox shows up again in my program files after I try to install, but still doesn't work. Don't know how to fix and I want to continue using Firefox and not other browsers. I guess the question is what do I do now when I still can't get Firefox to work? Please note that I need easily understandable response as I'm not very technologically savvy. I'm running Windows 10 on my desktop. The problem occurred when I tried to open Firefox this morning. Thanks

Chosen solution

I restarted my PC for another app that wasn't working correctly, opened that app and then tried Firefox again. It opened with no problem. I've now got firefox 45.0. But would love to understand why it wouldn't work when I first downloaded.

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jomacny
jomacny Question owner

Chosen Solution

I restarted my PC for another app that wasn't working correctly, opened that app and then tried Firefox again. It opened with no problem. I've now got firefox 45.0. But would love to understand why it wouldn't work when I first downloaded.

cor-el
cor-el
  • Moderator

Note that the error message about XPCOM missing usually happens because of a failed Firefox update that left you with a mixture of old and updated files in the Firefox program folder. This can happen in case security software was keeping a handle of some of the files in the Firefox program folder preventing Firefox from replacing all the files. You can do a clean reinstall to ensure that all files are replaced.

You can find the full version of the current Firefox release (45.0) in all languages and all operating systems here: