Go to Setup from the File menu. Set SLIP Port to 1 if your modem is using com1 and press enter. Exit and restart Trumpet. If your modem refuses to respond, then it may require an init string that is different than the default. Check your modem manual or the settings in a modem-related program that is working on your computer for a valid init string.
Press esc at the prompts and esc again to abort the script.
Go to 'setup.cmd' from the Dialler menu. Press enter for the number to keep the default. Next type your net id so that it will be used by default and press enter. Next type the new init string and press enter. Exit and restart Trumpet.