Business Objects default authentication change from "Enterprise" to AD

Hello,

This is my first post and question. I was told this was how to get support for Crystal Reports Business Objects version 11.5.

I've been asked to change the default authentication on the intranet web page from "Enterprise" to "Windows AD". Can someone advise on how to complete this task? I've looked through the administrator page and perused the registry.

Thank you,

Ben