Where do I change the windows xp log in menu?

Question

I am using windows XP, and for some reason I find myself with an old dialog box to login, which doesn´t even allow me to select an account. I used to have the classic menu coming with Xp.

I know I have to change an option somewhere, but I find myself unable to spot it ...

Could you tell me where it is ?

To sum up with images, I had this :

And now I have that :

Answer 1

You joined a windows server domain, or you/something have/has changed the way to login, a property of the user account settings in Control Panel:

Control Panel > User Accounts > Change login behaviour > check "Use welcome screen".