Setup a single instance of Win10 FF (all latest) with three different profiles - HOME, WORK, MEDIA ''(the junk)''. They all have their own colour schemes, set of bookmarks etc. Within "about:profiles" I have assigned HOME to be the default Problem: The default FF that keeps coming up is WORK, the least used of the profiles. The work around I found is in the Win startup menu and other shortcuts is to add -P HOME to the default. "C:\Program Files\Mozilla Firefox\firefox.exe" -P HOME On the desktop the different profiles are started with editing the three FF shortcuts and adding -P HOME or -P WORK or -P MEDIA to the start command.