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I have a 1-week old computer running Windows 10, and after loading Mozilla browser v54.0.1, I'm receiving the message "The update could not be installed. "

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  • Last reply by mattcamp

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Full error message is "The update could not be installed. Please make sure there are no other copies of Firefox running on your computer, and then restart Firefox to try again."

Full error message is "The update could not be installed. Please make sure there are no other copies of Firefox running on your computer, and then restart Firefox to try again."

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Open Task Manager (or Activity Monitor, on a Mac) and make sure only one Firefox process is running.

If you see two of them, kill either of them and try again.