Sync. Just an FYI... '''Firefox Sync IS NOT A DATA BACKUP SERVICE''' https://support.mozilla.org/en-US/kb/how-do-i-set-sync-my-computer https://support.mozilla.org/en-US/kb/how-do-i-choose-what-information-sync-firefox

Hi, I have the identical user name on both my Windows 10 laptop and Windows 11 laptop (it's actually a work computer). I was able to use the transplant procedure to pick up where I left off. Doing this requires being a little bit handy with Windows File Explorer. Here's how: '''(1) Create a backup of your existing profile folder on Windows 10''' You can open your current Firefox settings (AKA Firefox profile) folder using either * "3-bar" menu button > Help > More Troubleshooting Information * (menu bar) Help > More Troubleshooting Information * type or paste '''about:support''' in the address bar and press Enter In the first table on the page, find the '''Profile Folder''' row and click the "Open Folder" button. This should launch Windows' File Explorer listing the contents of your current profile folder. Click up or back one level so you can see the actual folder. This procedure involves dropping a copy of the folder (not individual contents of the folder) onto the new system. It's a good idea to close out of Firefox before making the copy to, for example, a removable USB drive or shared network storage. '''(2) Open Source folder on the new laptop''' In Windows File Explorer, open your USB drive or shared network storage location so you can see the folder you backed up on Windows 10. Resize that File Explorer window with the destination folder and move it to the left side of the screen. '''(3) Open Destination ''Profiles'' Folder''' Set Windows to show hidden files and folders: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files Open the receiving folder using either step-by-navigation, or by pasting a shortcut in the Windows 11 system search box and pressing Enter to launch it: * C:\Users\''username''\AppData\Roaming\Mozilla\Firefox\Profiles * ''Shortcut:'' %APPDATA%\Mozilla\Firefox\Profiles Resize that File Explorer window with the destination folder and move it to the right side of the screen. '''(4) Drop a copy of the old profile folder into the folder Firefox uses for profiles:''' In the source Profiles folder on the left, right-click the profile folder (weeg7ahd.default) and choose Copy. Important: copy the folder because you need to transfer the folder. This is not a method where you copy individual files. In the destination Profiles folder on the right side of the screen, right-click an empty area and choose Paste to paste the folder here. '''(5) Configure Firefox to use the old profile''' Make a note of the text after the dot on the profile folder, for example, '''default-release'''. You need the new profile name to match the old one in order for Firefox to regain use of your extensions and their data. Inside Firefox, type or paste '''about:profiles''' in the address bar and press Enter/Return to load it. * Click the "Create a New Profile" button, then click Next. * Assign the old profile name '''default''' and Firefox should show a proposed folder name with a new random part. * Click the "Choose Folder..." button and select the old profile folder you copy/pasted so that Firefox picks up the full old name. * Back in Firefox, click the Done button. After creating a new profile, Firefox usually makes it your default profile (for external links and the next startup). To test, scroll down to it and click the '''Launch profile in new browser''' button. ''Did it work?'' If so, you're done. If not, you can close that window without affecting your regular Firefox profile and change back to the profile you started with before this post. Click the '''Set as Default Profile''' button below your fresh profile.