We have 75 XP Pro/SP2-based classroom computers connected on the network. One
machine behaves strangely whether I log in as a teacher or as the system
admin. It connects to the server and can access the internet or streaming
media broadcast from within the school. I can ping other addresses inside and
outside of the school. If I try to map a drive to a network share, it says,
"The drive could not be mapped because no network was found." If I go to the
Machine Name tab of System Properties, there is a message at the bottom of
the box that says, "The identification of the computer cannot be changed
because: -Networking is not installed or is not properly configured."

I know the network is there and the machine is connecting to it in some
regard. How do I get it to allow me to map a drive? I tried installing a
second network card and re-installing the software for it, but that didn't
change anything. Thanks bery much.

Make sure the workstation service is running. These search result may help,

The drive could not be mapped because no network was found
Symptom: when trying to map a network drive, you may receive this error: “The drive could not be mapped because no network was found”...
http://www.chicagotech.net/Networking/ntbemapped1.htm
Workstation Service Issues
If a computer doesn’t have workstation service running and installed, you may have the following symptoms...
http://www.chicagotech.net/Networking/workstationservice1.htm

Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com
  We have 75 XP Pro/SP2-based classroom computers connected on the network. One
  machine behaves strangely whether I log in as a teacher or as the system
  admin. It connects to the server and can access the internet or streaming
  media broadcast from within the school. I can ping other addresses inside and
  outside of the school. If I try to map a drive to a network share, it says,
  "The drive could not be mapped because no network was found." If I go to the
  Machine Name tab of System Properties, there is a message at the bottom of
  the box that says, "The identification of the computer cannot be changed
  because: -Networking is not installed or is not properly configured."

  I know the network is there and the machine is connecting to it in some
  regard. How do I get it to allow me to map a drive? I tried installing a
  second network card and re-installing the software for it, but that didn't
  change anything. Thanks bery much.

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