I'm trying to connect my computer to the internet, and the network won't assign an IP address to the computer. There's nothing wrong with the internet - it works on my laptop, so what settings do I need to change on my computer?
Can you "ping" your router?
Does the PC attempt to connect to the router?
Going to assume your using XP here.
Control Panel-->Network Connections-->R.Click LAN Connection-->Properties-->Select Internet Protocol-->Properties (At this point check all is set to obtain automatically)-->Advanced (Under IP addresses does it show DHCP Enabled?)
Are you using a cable modem by any chance? Cable modems remember the MAC address of the first device they connect to and can't be connected to another without power cycling.