I have, by necessity, had to completely re-install windows 10 and all my software. I have got it working but there are niggles. Mozilla no longer places an indicator on my page when a new email arrives. Also Google chrome shows rubbish sites when I open a new Window whereas previously it was blank. I sure there are ways around this but if I can't find them!
I'm sure you just need to look in the settings and replicate them as they were before. By Mozilla, I assume you mean Thunderbird as your mail client, in which case, you should find a setting to display new email notifications in the Mail settings under Notifications. I don't use TB myself so I can't tell you exactly where they are.
With regards Chrome, you probably just need to change the Home page setting.
Thank you for your advice. the notification setting was not in Thunderbird, however it got me thinking and I found that it was in windows itself. Now sorted. thanks again.
Sometimes one just needs a nudge in the right direction. ;)