Can't connect to the internet

I've got a Compaq presario laptop with windows vista and just moved into a new house where we have virgin internet. although my flatmate's laptop will connect fine to the internet, mine will only connect to the local network, and recognises that it's connected. I've tried all the diagnostic tools on the laptop but it tells me to turn the router off and on again, except there's obviously no problem with the router as other laptops will connect. It also suggests getting a new IP address but that doesn't solve the problem either.

Any advice is welcome