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Firefox will not open. Tells me it can't find an unrelated file.

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When trying to start Firefox, I get a window saying "File not found" Then it tells me the specific file which has an xls extension. The file WAS a downloaded year end summary from Discover Card.

When trying to start Firefox, I get a window saying "File not found" Then it tells me the specific file which has an xls extension. The file WAS a downloaded year end summary from Discover Card.

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Try the Firefox SafeMode to see how it works there.
A troubleshooting mode, which disables most Add-ons.
(If you're not using it, switch to the Default Theme.)

  • You can open the Firefox 4.0+ SafeMode by holding the Shft key when you use the Firefox desktop or Start menu shortcut.
  • Or use the Help menu item, click on Restart with Add-ons Disabled... while Firefox is running.

Don't select anything right now, just use "Continue in SafeMode."