Here is a message that I just sent to SBC Globalnet, recorded here for posterity:
Tonight, I reinstalled an image of my program drive, with all previous software installed. I had been able to install SBC Globalnet DSL software on this image previously, and had successfully worked online with that SBC installation.
After reinstalling the drive image, I tried once again to install the SBC Globalnet software. As before, it was a hassle. I called tech support and, as before, we went through a variety of steps. Neither the technician nor the senior technician were able to help me. The senior tech's conclusion was that I needed to replace my modem.
I continued tinkering. I think rebooting was the crucial step, but I am not sure. Here are my notes, indicating most if not all of the steps we tried:
Error: SBC Yahoo! DSL Installer is unable to detect your modem.
Solution: power cycle the modem: unplug from power for 3-5 minutes. Make sure all devices are OK in Device Manager. Maybe disable ZoneAlarm and Windows firewall. In Device Manager / Network Connections, uninstall the ASUSTek Broadcom network adapter and reboot. In Network Connections, repair the "Limited or no connectivity" Local Area Connection item that comes up in place of the regular Broadcom item. Then reboot. At some point in the process of fiddling around with this, the activity light (fifth light) on the DSL modem will start to blink. That is the sign that you are on the way to having it all work OK.