My Thunderbird icon has disappeared from the task bar, where I go to use it several times daily. I tried R click on taskbar, taskbar settings, notification area, select which icons appear on taskbar, and turned Thunderbird to on, but it didn't work. It's maddening, because if I go to the program list and right click it shows "remove Thunderbird from taskbar" which indicates that according to Windows 10, the Thunderbird icon is on my taskbar already. Problem is I don't see it. Driving me crazy. Hope some knowledgeable person will take pity on a 77 year old who's been diagnosed with three different cancers in the last year. Thank you for any assistance.