Firefox doesn't have an "export" feature built into it for password data. Exactly what did you do to "export" your passwords? Did you use this extension? https://addons.mozilla.org/en-US/firefox/addon/password-exporter/ If so, see the screenshots on that page to see the Import function. If you copied the two files that are used for storing passwords from the old computer to back them up, just copy those 2 files into the Profile folder on the new computer to restore them. https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles