%APPDATA%\Mozilla\Firefox\Profiles

Hi elkhunter02, I'm sorry to hear about this problem. You can do a Firefox Refresh but since it will try to restore your last session anyway, let's set that option aside for the moment. There are a few possible reasons for the notice, but if it's a "tech support scam" site where they want you to call to fix a virus, and it comes back because you are killing Firefox and Firefox is doing a crash recovery, here are a couple different options -- I'll list them first, then give the details below: (A) Let the page show and then close it (B) Hide the session history files so Firefox doesn't restore the page '''(A) Escaping a Tech Support Scam Site''' There are a few common patterns to these annoying pages, and these are some techniques for closing them without having to take drastic measures. The "key" (ha ha) is the keyboard shortcut for closing the current tab, which is Ctrl+w (or on Mac, Command+w). Try it after each action to see whether it is available yet. (1) Large alert dialog - lots of text, possible background voice If you cancel this dialog (for example, by pressing the Esc key), it may reappear. After two or three appearances, Firefox should add a checkbox at the bottom of the dialog to stop the site from showing more alerts. Check that box and click OK to block further dialogs. (2) Authentication dialog - asks for username and password If you cancel this dialog, the page may reload and immediately show it again. Pressing the Esc key numerous times in a row can cancel the reload as well as the dialog. (3) Reacting to mouse movement Some pages have a script that detects when you are moving the mouse pointer up toward the tab bar and takes action to show another dialog, or moves to full screen view to hide the toolbar area. On these pages, the keyboard shortcut is essential. Hopefully this will let you close problem pages without having to "force quit" Firefox. (I don't recommend using that method because the tab will come back during automatic crash recovery anyway.) ''Note for the future:'' Often these scam pages are promoted through ad networks. As a defensive measure, you could consider using an add-on that is effective at blocking ads, such as: https://addons.mozilla.org/firefox/addon/ublock-origin/ As with any content blocker, this will cause problems on some sites, so keep an eye on its toolbar button in case you need to make an exception to get a page to load properly. '''(B) Hiding Session History Files''' Type or paste the following into the Windows Run dialog or the system search box, and press Enter to launch Windows Explorer into this folder: %APPDATA%\Mozilla\Firefox\Profiles Windows should expand that to show the hidden folder: C:\Users\''your-user-name''\AppData\Roaming\Mozilla\Firefox\Profiles There, you should see at least one semi-randomly-named profile folder -- for example, "a23bc4z7.default". (If you see more than one, you'll want to figure out which one has the unwanted session history in it by checking each one.) Double-click into the profile folder. Next: * Right-click the '''sessionstore-backups''' folder and rename it to '''sessionstore-backupsOLD''' (later you can mine the files in this folder for any important tabs you want to restore) * Check for any files with these names and: ** sessionstore.jsonlz4 - created by Firefox 56-63 when it shuts down normally - rename to sessionstoreOLD.jsonlz4 ** sessionstore.js - created by Firefox 55 and earlier when it shuts down normally - rename to sessionstoreOLD.js ** sessionstore.bak - obsolete file from years ago - delete When you start Firefox up again, it should just show the home page. Success? If you need to read the contents of any of those hidden files, you can use this tool on my websites to extract out a list of the tabs: https://www.jeffersonscher.com/ffu/scrounger.html