In Windows 2000 or XP any user who logs on to a computer has rights to create a basic local user account on that machine. Although these created users will only be in the users group and not power users or administrators of the machine, this is still something that should not be happening on a regular basis as it can create security loopholes in your workstations.
To remedy this situation you can right click on my computer, select manage, and browse to the groups section under the local users and groups heading. Double clicking the users group should display all of its members. You will notice in this group that NT AUTORITY/INTERACTIVE is a member. Selecting this account and clicking remove will remove it from the group and prevent users from creating other local user accounts.
Chris Sanders is the network administrator for one of the largest public school systems in the state of Kentucky. Chris's specialties include general network administration, windows server 2003, wireless networking, and security. You can view Chris' personal website at www.chrissanders.org.