Thunderbird will not open, and I need to retrieve some emails from family and 2 friends who have died of Covid19. Can anyone please help me?

Error says TB already running. I use End Task to close TB. Reboot. But TB still does not open. Please help. I am running windows 10 home. Recently, Microsoft forced a Windows Update. After that, Mozilla Firefox and Mozilla Thunderbird Both will not open. Same error message over and over again: "Is already running. Need to close previous version." So, I use End Task. Then reboot. Same error message over and over again. How can I retrieve family emails, when TB will not open. I have spent 7 days on this. System restore does not work. Please, I kindly request someone please help me to retrieve these emails. Thank you very much.