Issue : On Windows 10 Pro : we can't lunch new instances of Firefox when Firefox is started by Logon Batch Script at startup with GPO Configuration : - Windows 10 PRO - Firefox 67.0.2 (x64) - Server 2016 and Active Diretory Domain Redo the bug with : - Create a GPO with Logon Batch Script with the command DOS : start http://portail.artzainak.fr - Logon an user on a computer with this GPO. - Firefox is automaticaly started with the URL BUG : we can't lunch new instances of Firefox : Open a new windows of firefox not working. Open an URL Shortcut not working. No error message. Just firefox not want to open new windows. If you close Firefox and you open Firefox all is working fine until the next reboot and the next Logon Batch Script. The issue is on Windows 10 PRO and Firefox 67.0.2 (x64) and Logon Batch Script with command start "your URL" This work fine on windows XP and windows 7. Have you got a solution?