bigland

Check network layer:

when you are using Automatic obtained IP Address
- go "start" menu -> type "cmd" -> click "ok" -> on DOS window type in "ipconfig", check whether the ip address is syn with your router DHCP setting. (eg. you should get something like 192.168.1.x, if your router DHCP is using 192.168.1.0 - subnet mask 255.255.255.0)
- If the ip addressing is correct, then type in "ping <gateway ip address>".  (gateway ip address will be the one showing on ur router setting, eg, 192.168.1.1)
- if you can ping the gateway ip address with "reply from ...." message. then the network layer is working fine. Then it may be the DNS / proxy problem.
- if it is DNS problem, use correct DNS server either on ur router or pc.
- if it is proxy problem, use correct proxy setting on ur web browser.