The group already exists.
You tried to create a group with a group name that already exists.
Use a different group name for the new group. To display a list of group names established on the server, type NET GROUP if you are running the Windows 2000 Server. If you are running Windows 2000, type NET GROUP /domain. Your Windows 2000 workstation must be a member of a domain that is running Windows 2000 Server. Otherwise, you will see a message that tells you that NET GROUP is a Windows 2000 Server command only.