No web pages displayed, wireless connection

I was wondering if anyone has any ideas as to why my internet connection isn't working?

I have a wireless adapter which is connected to a shared router - I was supplied with an IP address, DNS etc to enable me access to the router. My computer can see the router and has a strong signal with the relevant info in the prefernces. However, internet explorer cannot display web pages. Any ideas? I'm using Windows XP. I've tried re installing all of the drivers and the problem has persisted.

Thanks in advance
Sarah