The first thing is to determine what kind of modem you have. Most software/winmodems won't work with linux and if you have one of these then you will be better off getting what they call a hardware modem that will work on linux. Post the results of
to help tell what kind of modem you have. There is a modem scan tool on this web site that might also help to determine what kind of modem you have. http://linmodems.technion.ac.il/
. Once you know what kind of modem you have you still might have to load the drivers for the modem. Loading the driver for the modem will vary depending on what kind of modem it is.
A standard install of Ubuntu comes with the tools to use dial-up if wvdial isn't installed. Here is link to how to set up dialup http://www.ubuntugeek.com/setting-up...in-ubuntu.html