I was about to suggest using "secpol.msc" from the "run" box...
I tried to do that, and it did not even exist on this system!
Then I tried manually launching microsoft management console from the
"run" box... I fished around in the "add/remove snap-ins" for "users and
groups" and tried to get that running...
--snip--
This computer is running Windows Vista Home Basic. This snap-in may not
be used with this version of Windows. To manage user accounts for this
computer, use the User Accounts tool in the Control Panel.
--snip--
Further digging led me to this article:
http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=1250602&SiteID=17
So... if you have "windows vista home basic" you're out of luck (there's
no "official" way to administer these settings, and even if you try
installing and running such a snap-in manually, it will refuse to launch!)
In a few weeks my "anytime upgrade" DVDs for windows ultimate will be
coming in the mail, but sorry, I don't have an answer for you today.