During the compatibility check the system came up with the following message:
"Replacement logon software
An application has replaced the Microsoft Windows logon software on your computer, such as a biometric logon or smart card logon application. This program might no longer function after you upgrade, which might prevent you from logging on to your computer. After you upgrade, even if the program functions, some operating system features might not be available. It is recommended that you uninstall this software before continuing with the upgrade
For more information about this driver, contact the device manufacturer or visit the manufacturer's Web site"
But they don't name software or manufacturer and I can't get past the message.
I don't know what Replacement logon software I might have. There is an identical previous question on EE but that was on a Citrix server. I don't have Citrix.
The other option is a complete install. That prompt says "it MAY cause me to lose data". What are the chances of that?