You can use TweakUI or Sysinternals Autologon.
For Windows x64, a company called NeoSmart developed a 64bit version of TweakUI that basically looks and behaves pretty much exactly like Microsoft's TweakUI.
Also, Microsoft now owns Sysinternals, which they puchased from the developer Mark Russinovich a while back. I tested Sysinternals Autologon (released Nov 1, 2006) on Windows 7 and it worked fine for me.
Granted, I get that the OP wants to disable Autologon. But for others that want to enable it, consider this...
While Autologon is a very convenient feature (I've used it myself in the past), it's generally not a good practice from a security standpoint. I always set a password (I'm amazed at how many general end users do not even set a password on their PC) and disable or do not use Autologon. Besides, always having to type your password makes it less likely that you will forget the password.
Here comes the "but this is my home computer and windows passwords are easy to hack/crack" argument. True, but suppose your laptop got stolen (this has happened to me recently) or someone broke into your home and stole your computer.
You'll probably be glad you set a password (or if you're like me, also use encryption). Why make it super easy for a thief or hacker to get into your PC? Even if they can eventually bypass the password, make 'em work for it.
People always say "it's just my home PC", but you'd be surprised how many of those people also forget that they actually do have some sensitive data on their PC such as TurboTax data, Quicken data, PDF copies of loan applications, and all sorts of stuff like that.
These days, we live in a world where lax security is no longer an option, (unless you want your PC and data to get raped). The argument that hackers and theives only go after large corporations no longer holds any water. They go for the low hanging fruit...the easy targets. If they can't get any useful data from your PC, they can at least use it as a bot to perform other actions for them (why do you think there are so many viruses and spyware?).
If you want to use Autologon, then that's your personal choice. But just make sure you know and understand the risks.