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Have an xpcom not found error, reinstall executable does not run!

  • 7 cavab
  • 1 has this problem
  • 2 views
  • Last reply by engg1984

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I am on Windows Vista, German version. I deleted an old folder which I thought wasn't used - unfortunately, it was the Firefox folder, and only some files were deleted. Ever since, I keep getting the error "xpcom not found" when I try to run firefox. I tried to download a fresh copy of the installable. When I run it, it asks me whether I wish to run it as the current user, or another one. If I click on "current user", then nothing happens. Nothing at all. If I click on the user "administrator", along with my Windows password, then it says my credentials are invalid. I have no other user on my laptop; my current user has administrator rights. What do I do, please?

I am on Windows Vista, German version. I deleted an old folder which I thought wasn't used - unfortunately, it was the Firefox folder, and only some files were deleted. Ever since, I keep getting the error "xpcom not found" when I try to run firefox. I tried to download a fresh copy of the installable. When I run it, it asks me whether I wish to run it as the current user, or another one. If I click on "current user", then nothing happens. Nothing at all. If I click on the user "administrator", along with my Windows password, then it says my credentials are invalid. I have no other user on my laptop; my current user has administrator rights. What do I do, please?

All Replies (7)

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Hello,

Certain Firefox problems can be solved by performing a Clean reinstall. This means you remove Firefox program files and then reinstall Firefox. Please follow these steps:

Note: You might want to print these steps or view them in another browser.

  1. Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
  2. After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
  3. Delete the Firefox installation folder, which is located in one of these locations, by default:
    • Windows:
      • C:\Program Files\Mozilla Firefox
      • C:\Program Files (x86)\Mozilla Firefox
    • Mac: Delete Firefox from the Applications folder.
    • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
  4. Now, go ahead and reinstall Firefox:
    1. Double-click the downloaded installation file and go through the steps of the installation wizard.
    2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

Please report back to see if this helped you!

Thank you.

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Thanks; but that doesn't work, as:

> Double-click the downloaded installation file and go through the steps of the installation wizard.

is one of the things that doesn't work for me (I can download the installation file, but can't seem to execute it; please see original problem description)

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Try the full (offline) installer in case the stub installer gives problems.

You can find the full version of the latest Firefox 24.0 release in all languages and for all Operating Systems here:

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Thanks for your response. I would love to try a full/offline installer, as opposed to a stub.

However, the link you provided is the standard Firefox link, and, for Windows, English (US), has only the "stub" installer. When I try to run it, an "extracting" message box comes up, followed by the problem mentioned in my original post. Nothing happens.

1. I also tried to restore Windows to a date when Firefox was working. No joy.

2. Firefox portable works fine.

Can I somehow get the xpcom dll file from a safe source?

Please help, otherwise I won't be able to use my favorite browser. I type this in IE (ughh).

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I searched the Web for an offline installer, and found what appeared to be one.

https://support.mozilla.org/en-US/questions/964819 https://ftp.mozilla.org/pub/mozilla.org/firefox/releases/22.0/win32/en-US/Firefox%20Setup%2022.0.exe

Behaved exactly as the "stub". Still no joy.

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There is also just the plain https://www.mozilla.org/en-US/firefox/all/ which has the full installer.

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All right - problem fixed. Had to change the properties (right click, properties) of the installer to "allow to run as administrator" (ticking the box). That's it.