On an old MacBook Air running OS X, I'm unable to get the password utility to work. After booting into recovery mode, navigating to Utilities> Terminal, and running the reset password command opens a window, but all the fields are greyed out.
[Re-Titled by Moderator]
Original Title: Password reset
I can think of no remedy other than to select Reinstall OS X from that Recovery window. You might also consider forcing that Mac to boot macOS Internet Recovery by holding ⌘ ⌥ R at startup (command option R).
A viable Internet connection is a prerequisite.
Do you recall the particular model MacBook Air, or the installed macOS version?
The first thing that happens in recovery mode is prompts for connecting to a WiFi network, which I did. The WiFi icon is there and connected. This is an old machine (A1466), Intel chip, Yosemite.
Greyed-out fields in password utility on old MacBook Air
