Yesterday my company of approximately 30 employees, had the network come to a stand still. I restarted the router, and the switch that houses all the ports for the ethernet cables to connect to. I restarted that too. Thankfully all came back up and everyone was back online. However, from my server 2003 I cannot ping some computers that are located in a certain part of the building. They however can access my network and proceed like normal. They each have their own IP address. What can the problem be? My users have XP and windows server 2003 will not recognize a section of the building.