By Paul Thurrott
With Windows 8, Microsoft is bringing a number of technologies and user experiences from the mobile world into its desktop OS for the first time, a blending of the old and then new that will confuse some users. But while some of the new mobile-based experiences in Windows 8 will make sense on traditional desktop and portable computers, some will not. And the Windows Phone-like Lock screen can rightfully be seen as an unnecessary extra step at boot time. Letís get rid of it.
Source: Paul Thurott's SuperSite for Windows
I disabled the lock screen so long ago I don't remember how I did it anymore.
It does appear if I log out, but never when I'm booting to start with.
I just went through the link above and I had already done that at some point because it was disabled.