Windows 2003 RIS Server

Archived from groups: microsoft.public.win2000.setup_deployment (More info?)

We currently have a Windows 2000 RIS server for building
desktops and servers. Since we're running out of room on
our current box and cannot add more space I thought that
I would build a new server with Windows 2003. When I
install RIS I get the following error:

"You must be an administrator of this computer to run
this utility.

Log off, and then log on using an administrator account."

I was logged in as a Domain Admin when I get this error.
I've tried adding my AD account as local admin, no dice.
When I've tried to do this as the local admin, I get an
error because that account doesn't have any access to the
domain. I've tried this on a few different servers with
the same result. Thanks