Linksys WUSB54GC 802.11g/b can find access point...

Question

HeyI've Recently brought A Linksys WUSB54GC 802.11g/b Wireless adapter for my Desktop PC, after installing the software and connecting to the router I find I am unable to access the internet. The Wireless moniter tells me that it can connect to he access point but not the internet, I Have also go a laptop with a built in wireless adapter which connects to the internet perfectly, can anyone suggest some way to overcome this?