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

Fiefox won't open.get mesage "The procedure entry point PR_Clo~e could not be located in the dynamic link library nss3.dll."

  • 2 replies
  • 1 has this problem
  • 1 view
  • Last reply by cor-el

more options

Firefox won't open. I get message: "The procedure entry point PR_Clo~e could not be located in the dynamic link library nss3.dll." Followed by message: "Couldn't load XPCOM." Tried uninstalling Firefox and data and then re-installing. Firefox still will not open and still get same error messages.

Firefox won't open. I get message: "The procedure entry point PR_Clo~e could not be located in the dynamic link library nss3.dll." Followed by message: "Couldn't load XPCOM." Tried uninstalling Firefox and data and then re-installing. Firefox still will not open and still get same error messages.

All Replies (2)

more options

nss3.dll = Network Security Services

XPCOM may be Firefox

What are you using as your protection programs? Download their current full installers. Remove the old, then use the new installers.

more options

Sounds that your Firefox installation is corrupted.

Do a clean reinstall of the current Firefox release and delete the Firefox program folder before installing a fresh copy of the current Firefox release.

If possible uninstall your current Firefox version to cleanup the Windows Registry and settings in security software.

  • do NOT remove "personal data" when you uninstall the current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including data in profiles created by other Firefox versions

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

  • (64-bit Firefox) "C:\Program Files\Mozilla Firefox\"
  • (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you reinstall or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

If you keep having problems then you can create a new profile to test if your current profile is causing the problem.


Reinstall Firefox