Inspiron 2200 Networking Problem

I just added a new Inspiron 2200 to a home wireless network.  The access point and router are Linksys, connected to a cable modem.  I can access the internet from the 2200 and I can ping other computers on the network.  The 2200 can not ping itself nor can it be pinged by other computers.  The Linksys equipment seems to be working fine and the router name server is ok although the 2200 can not ping by name.  The 2200 can not 'see' any other computers on the network.  Other computers can 'see' the 2200 but can not access it.  The firewalls are turned off and I repaired all of the connections.  I spent several hours on the Microsoft and Dell websites troubleshooting but to no avail.  I am guessing there is an obscure check box somewhere that I am over looking.  Please, help!