Unable to configure network on Ubuntu 10.10

Hi All,

I'm fairly new to Ubuntu, though I have experience in other Linuxes (RedHat, Centos, SuSe).

I have setup a PC (for one of the kids) at home with Ubuntu 10.10 without problems, but now I'm stuck at the network.
I would like to setup Wireless (simple wlan at home 128-bit WEP), but it will not give me DHCP.
Also tried setting it up wired (not preffered, because I have to put a cable through the hallway), but also I do not get DHCP.

I will try later on rebooting the modem/router.

The wlan is seen as: Reaktek RTL8180L 802.11b (rev 20)
The wired is seen as: SIS900 PCI Fast Ethernet (rev 91)

Please could someone provide any clues on where to look. I cannot upload any info, becasue I can't get the PC connected to the Internet.