<i>duplicate of [/questions/1509077] thread</i> Hi. There is a new feature of Firefox that bothers me. It is when I drag tabs around the top, they try to group when I don't want them to. So I go to about:config and find the "browser.tabs.groups.enabled" key and set it to false. But when I restart Firefox, the change reverts. How do I fix this so the change stays? I've already tried going to Menu->Help->More troubleshooting information->Profile Folder->Open folder, but there is no "user.js" file there. Do I have to do a Firefox reset to fix this? I hope not... Note that I'm pretty sure that other settings that I change do not revert when I restart Firefox. Right now, it seems to be just this one about:config setting, unless the new version of Firefox reverts all manually changed about:config settings upon restart. Thanx in advance for any help.