Minor Log-in issue!

Hello again all!
Yes, I’m back with another tiny problem!
I use Ubuntu MATE on both my Desktop PC, and my Raspberry Pi.
When I start up my PC it loads the OS as normal, and I get straight to the desktop.
When I start my RPi it stops booting at a login window.
In my RPi’s Control Center is an icon for: "LightDM GTK+ Greeter. My PC has “Login Window” instead.
Both work very differently! LightDM GTK+ has NO User settings, so there’s no way to tell it NOT to ask for a user name and password every time I start the machine.
So, is there a way around this?