Hmm... DHCP is a service/server which automatically gives devices on your network (amongst other things) an IP address.
However, it seems that your machine has got an IP address, so it might not be that...
To log into your router, visit 192.168.1.1 on a machine which can connect to the internet. By default, the username and password are both "admin".
Have a look through the settings there. If you find anything to do with "MAC Filtering", disable it. And if you found that DHCP was disabled (which I doubt), then enable it.
Do you know if your Wi-Fi Connection is encrypted with WPA or Wi-Fi?