Troubleshooting large computer systems is often highly collaborative. Because these systems consist of complex infrastructures with many interdependent components, expertise is spread across people and organizations. Those who administer such systems are faced with cognitive and social challenges, including the establishment of common ground and coordination of attention, as they troubleshoot in collaboration with peers, technical support, and software application developers. To investigate these aspects of administration work, we take a distributed cognition approach to interpreting a specific instance of problem-solving in administering a Web-based system, examining the movement of representational states across media in a single system administrator’s environment. We also apply the idea of language use as a joint activity to understand how discourse attributes affect what is accomplished collaboratively. Our analysis focuses on information flow among participants and other sources and how these affect what information is attended to, transmitted, and used.