Can't access internet from one wireless network

I'm having a strange problem. I'm trying to set-up a desktop on my wireless network but have been unable to access the internet. It shows packets sent, but none received. I'm able to connect to the network (signal excellent), but not the internet.

My laptop is running just fine on the network wirelessly.

I just tried to access an unsecured wireless network that is showing up in range and was able to connect and access the internet from the desktop.

I'm using a Linksys PCI adapter and a Netgear router.

Any suggestions?

Thanks in advance.

Dari10