>I am installing an email software on NT Server 3.51 Service Pack 5.
>
>First step of the installation is to create a New Global Group by accessing the User Manager for Domains window. By, New Global Group is disable. How can I have it enable?
>
>I am logged as an administrator.

do you have several domains in your network setup?
if not setting a new group for you domain should be enough I think

Arnon