I logged in as administrator, opened system properties, clicked on the advanced tab, then clicked on "Settings" under "User Profiles". This then brought up the list of user profiles. They were all listed as "account unknown". I attempted to delete them, but the "delete" and "copy to" buttons are grayed out.
I also opened "user accounts" in the control panel, but none of them were listed there.
I've done a fair amount of reading on the web about this problem and haven't been able to find a solution.
Could anyone shed some light on this?