Network Administration: Windows User Deletion
Deleting a user account in Windows Server 2008 is surprisingly easy. Deleting a user account is a permanent, non-reversible action. Do it only if you’re absolutely sure that you’ll never want to restore the user’s account. If there is any possibility of restoring the account later, you should disable the account instead of deleting it. Just follow these steps:
Log on as an administrator.
You must have administrator privileges in order to perform this procedure.
Choose Start→Administrative Tools→Active Directory Users and Computers.
The Active Directory Users and Computers management console appears.
Click Users in the console tree.
In the details pane, right-click the user that you want to delete and then choose Delete.
Windows asks whether you really want to delete the user, just in case you’re kidding.
Poof! The user account is deleted.