Login Window Format


We are using 3 Macbook Pros and 1 Mac Mini. Two of the MBPs started with Leopard, then upgraded through Snow Leopard, Mountain Lion, Mavericks, Yosemite. The other MBP and the Mini started with Snow Leopard and upgraded through the ranks to Yosemite.

Somehow, the 2010 MBP is stuck with the pre-Lion login screen. I can't recall if a setting change caused it to revert to the old login format, but I'd like to see it use the current (introduced with Lion) login window.

Is anyone aware of a key, possibly in /library/preferences/com.apple.loginwindow, or some other global default setting, that would cause the current systems to use to the pre-Lion login window?

Thank you.
Somewhere in your updates, the install skipped the ‘new’ file install. Go to the APP store and do a fresh download of 10.10.1 and install.