how do I restore a deleted profile and then remove the profile feature completely so I never have to see it in my application menu again?

Sorry this happened. The key thing to understand is that Firefox always runs inside one profile, and your settings, passwords, extensions and history are stored in that profile's folder. Deleting the profile deletes that folder, which is why the settings went with it. The good news is your original profile may still be there and just no longer selected. Work through this in order: 1. Type about:profiles in the address bar and press Enter. 2. Look at the list of profiles. If you see another one besides the current one (the original is usually called default-release), click Launch profile in new browser under it. If your settings are back in that window, return to about:profiles and click Set as default profile under that same profile. 3. If no second profile is listed, press the Windows key + R, type %APPDATA%\Mozilla\Firefox\Profiles and press Enter. If a folder with your old data is still there but not listed in about:profiles, use Create a New Profile on the about:profiles page and use the Choose Folder option to point it at that folder, then set it as the default. 4. If the folder is truly gone, the data can only come back from outside Firefox: check the Recycle Bin and any backup or Previous Versions copy of the Profiles folder, and if you had Firefox Sync turned on, sign in to the same Mozilla account in Firefox and your synced settings, bookmarks and passwords should come back down. As for switching the feature off: there is no supported way to remove profiles completely, because Firefox itself needs one profile to store everything in. The safest way to never be bothered by it again is to end up with just the one restored default profile and leave the profile switcher in the menu unused. The coloured bar in the menu belongs to the current profile's colour, and you can soften that by opening the menu, going into your profile to edit it, and picking a plain/default colour. Please tell us what you see on the about:profiles page, and we can guide you from there.