Ok, basic questions first.
Did you install the Ethernet driver package? If so, what version?
Is your router configured to only allow connections if, for example, MAC address matches?
Thanks for your help. I downloaded the driver bundle and have been going thru them but so far haven't found the correct one. The router is configured correctly and has no problem with the other computers.
In the device manager there are a bunch of items listed under network, all having a peculiar bang mark. I'm not looking at it now, I'm sure it isn't "network" heading but something related to that.