Thank you for helping.
Just before following your suggestion, I tried to uninstall it using the Windows App & Features menu but only the 'Modify' option was present. I tried it anyway and it gave me an option to repair. I tried the repair but it complains about not having enough privilege for tons of files so I cancelled.
So I used the uninstall tool in safe mode as suggested in the page you linked. The product got uninstalled ok.
I then tried the manual install from scratch. It seemed to install and asked me for my product key. Then asked for a few privacy and settings questions but at the end it said the installation failed and asked my to run the troubleshooter...
The troubleshooter suggested I reboot and reinstall. I did and this time I did not enter my product key and the installation worked.
My ratings:
Your support: 10/10
eset update: 0/10 since it cannot update itself without making a mess of itself
eset uninstalling: 5/10 very troublesome
eset installing: 5/10 needs two trials to get it to install
Thanks again for your help.