Alright, assuming a few things:
- OS is WinXP ?!
- Router is configured right ?!
- DHCP is enabled on the router ?!
Check this:
- Start -> Control Panel -> Network and Internet Connections -> Network Connections -> 1. make sure there are not multiple adapters enabled, 2. make sure nothing is 'bridged', 3. right-click on the enabled adapter icon ->
Properties -> click on Internet Protocol (TCP/IP), then click on Properties ->
1. is it set to obtain IP and DNS Server addresses automatically ? - If not, you might want to set it to obtain that info automatically.
If that doesn't do:
Open Internet Explorer, click on Tools -> Internet Options -> Connections -> LAN Settings -> Place a check mark in Detect settings automatically, if there is not one already ... and see whether that helps ...
If nothing works, open up a Command Prompt by clicking Start -> Run -> type: cmd -> press Enter, then type:
ipconfig /release ---- then press Enter, and then type:
ipconfig /renew ---- then press Enter
Let us know whether it renews the IP without a problem, if it does ... does the Internet work ?