Assuming that you have actually connected to the wifi network and passed any security hurdles (WEP / WPA(2), MAC address filtering), you will not be able to use the wifi network until the PC has a valid IP configuration for the network.
This is normally provided via DHCP, with the PC configured as a DHCP client and the wifi access point / router acting as the DHCP server.
If the router is not acting as a DHCP server, or has insufficient addresses for the number of connected clients, then the PC won't get an IP address.
Can you see what (if any) IP address the netbook has? If its IP address is in the range 169.254.0.1 through 169.254.255.254, then it is almost certainly a DHCP problem.
It may be simplest to provide the IP configuration manually - IP address, subnet mask, default gateway and DNS servers - either permanently or for troubleshooting purposes.
You don't indicate what OS the netbook is running, but Windows supports an "alternate configuration", so that you can have DHCP as the principal means of obtaining IP configuration, with an alternate fixed IP configuration "hard-coded".
SD