I have four computers setup to network. The networking has worked fine until recently. Only one of the computers is having trouble. When you try to connect to the network it says the network path is not found. I have disabled the firewall. Other computers can find this computer. Access to the internet through the router is OK.

Keep firewall enabled

If this just started happening, have you tried a system resotere point to before this started happening?

Use System Restore to Undo Changes if Problems Occur (http://www.microsoft.com/windowsxp/using/helpandsupport/learnmore/systemrestore.mspx)