This is an executable zip file that can unzip onto a floppy. Works on most U.S. Robotics Data/Fax 33.6k and 56k modems bought between January 1996 to present except Winmodems.
In Control Panel, double click Modems and remove all U.S. Robotics modems. Restart your computer. When prompted, select "Change" or "Have Disk" and point the installation to the 3.5-inch disk. Select the appropriate model and then follow the prompts to finish the installation.