A user group is a collection of user accounts that all have the same security rights. User groups are also sometimes referred to as security groups.
A user account can be a member of more than one group. The two most common user groups are the standard user group and the administrator group, but there are others. A user account is often referred to by the user group it's in (for example, an account in the standard user group is called a standard account). If you have an administrator account, you can create custom user groups, move accounts from one group to another, and add or remove accounts from different groups. When you create a custom user group, you can choose which rights to assign.
These steps cannot be completed on Windows Vista Starter, Windows Vista Home Basic, and Windows Vista Home Premium.
Open Microsoft Management Console by clicking the Start button , typing mmc into the Search box, and then pressing ENTER.
If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
In the left pane, click Local Users and Groups.
If you don't see Local Users and Groups, it's probably because that snap-in has not been added to Microsoft Management Console. Follow these steps to install it:
In Microsoft Management Console, click the File menu, and then click Add/Remove Snap-in.
Click Local Users and Groups, and then click Add.
Click Local computer, and then click Finish.
Double-click the Groups folder.
Click Action, and then click New Group.
Type a group name and a description.
Click Add, and then type the name of the user account.
Click Check Names, and then click OK.