Actually, I am running 64bit Windows 10 and have been for some time.
Many of the apps and programs are 64bit since they were auto installed.
I suppose I will install 64bit Thunderbird when it is offered normally
where I will not have to go thru a manual uninstall of the 32bit
version. Hopefully, the 64bit install will have progressed to the point
where all that will be done automagically :). I look forward to that
day. - Thanks for the feedback.