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When try to open Firefox, getting message "firefox.exe is not a valid WIN 32 program"

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

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Have been using Firefox for many years on PC running Windows XP. Updated Firefox Monday. Ever since, I cannot open it. Keep getting error message described above.

Have been using Firefox for many years on PC running Windows XP. Updated Firefox Monday. Ever since, I cannot open it. Keep getting error message described above.

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Do a clean (re-)install:

  • Download a fresh Firefox copy and save the file to the desktop.
  • Uninstall your current Firefox version and remove the Firefox program folder before installing that copy of the Firefox installer.
  • Do not remove personal data if you uninstall the current version.
  • It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.

Your bookmarks and other profile data are stored elsewhere (not in the Firefox program folder) and won't be affected by a reinstall, but make sure that you do not select to remove personal data if you uninstall Firefox.