They're both right. Winmodems behave like normal modems when a driver is present on the computer to make it imitate the normal functions performed by a modem's hardware. Often, these drivers are only made for windows, giving software modems the name of "winmodems". There are some winmodems however that have linux drivers, and are therefore known as linmodems. Fun eh?
What you need to do is find out the Manufacturer, name of the modem and chipset name then go to http://www.linmodems.org
and search for it there. Failing that, take your modem information and search for linux drivers on google.