So you're a brand-new AT&T DSL customer, you've never had a DSL line with them, 
and you've got a "SpeedStream" modem?

Did they send you that stupid DSL setup CD loaded with bloatware?

DON'T USE IT!

You only need to create a new account with them and enter that login/password 
into your SpeedStream's configuration.  You only need a network cable, a web 
browser, and an Internet connection.

So you say, "HA HA that's a catch 22 you fool" but you can really use any 
Internet connection to create this account.  Go to your sister's house, 
connect to your neighbor's unprotected wireless access point, take a laptop
to a cafe with free WiFi, or do it at work!

On a computer which is already online, go to:

https://sbcreg.sbcglobal.net/

Don't plan on using Firefox. AT&T isn't enlightened.  You're best off with 
Internet Explorer.

Go through their little registration process; you only need to populate the
mandatory fields.

As soon as it starts talking about installing or "updating software components"
you can discontinue the process.  By that time you've already set up as much
as you need.  To be safe, you might just leave that browser window open while
you try out your new username/password.

By the way, AT&T tells you to write down that username/password, and I agree
with them.  In fact, post it right on your modem!  Password recovery of PPPoE
accounts is a PITA!

If you're sitting in your car leeching off of the wireless access point you
found down the street, go back home now.

Connect a network cable directly from your computer to the modem's "ethernet"
port.  Wait a couple of moments for your computer to be assigned a new IP
by the modem. (If you aren't configured to use DHCP, you'd better do that)

Now, in a new browser tab or window, connect to the modem's web interface.
On SpeedStream models, this is typically http://192.168.0.1/

It might ask for the Modem Access Code.  That's on a sticker on the 
underside of the modem.

Right off the bat, once you're in, it should prompt for your username and
password.  That's the one you created on that sbcglobal.net website.  And
that should be it.  Your modem should already be showing you with its 
pretty green LEDs that you're online.

If not, maybe you need to install their lousy software afterall.