I want to configure my DLink USB modem to Ubuntu 12.10, it does not detect it.
Open up a terminal from Applications -> Accessories. Type:
gksu gedit /etc/modules
At the bottom of the file, make two new lines, like this:
Then close the editor program and save it. Reboot the computer[.]
I found this solution in Maduka Jayalath's answer to Micromax MMX 310G Data Card is not being recognized as a modem.