Click START, RUN > Type "control userpasswords2" Without quotes.
Wait for the dialog box to appear and Uncheck "Users must enter a password to log on"
It will prompt you to type in the default account you want windows to log into along with the password if any.
You can use stardock bootskin to change your boot screen. Its free
You can edit your registry and change the SHELL from EXPLORER.exe to what ever program you want to boot.
Tons of ways to do it.