Thunderbird was upgraded omn my Windows 10 machine and will not open. When I try to open this mesage comes up "Your computer must be restarted to complete a previous upgrade of Thunderbird. Do you want to restart now?". I tried the restart many times but the message keeps coming up. I tried downloading the current version and when it tries to repair the install, the same message comes up. So then I just tried to uninstall it from my computer and the same message continues to come up. Can someone offer some advice? I have been a Thunderbird user for about 30 years and it always has worked well. Thank You