Though we recommend you to avoid using multiple low-cost fax modems for faxing, we get asked this question a lot. Here is a simple step by step guide showing you how to install multiple U.S. Robotics V.92 USR5637 56K USB Fax modems on Windows XP:

• Connect the modems to computer, and install modems drivers;
• Open Joyfax Broadcast, click Options button on the toolbar, choose Fax Devices, click Detect Devices..., only one U.S. Robotics V.92 USB Modem could be found in the devices list;
• Click Exit on File menu to quit Joyfax Broadcast;
• Right-click My Computer, click Properties, click the Hardware tab, and then clickDevice Manager, double-click Modems:
  
  Modems which name contains a # character that cannot be recognized with Joyfax Broadcast;
• In order to fix this problem you have to update the Modem drivers manually. To prepare for updating modem drivers:
  • Click here to download the lastest release drivers: i.e: USR5637-2kXpVista32-bit.exe;
  • Extract the drivers to C:\USR\5637, double-click theUSR5637_2k_XP_Vista_32bit.inf file to open with Notepad;
  • Replace the string Modem2 = "U.S. Robotics V.92 USB Modem" asModem2 = "U.S. Robotics V.92 USB Modem II" (The string name may be Modem1PCI, Modem1EXT, Modem1EXTPNP and Modem1USB etc...);
    
  • On File menu, click Save As..., type "USR5637_II.inf"(Include the inverted commas), click Save, and then close Notepad.
• Right-click U.S. Robotics V.92 USB Modem #2 modem, select Update Driver;
• The Hardware Update Wizard will begin: Select No, not this time, click Next; Select Install from a specific location(Advanced) and click Next; Select Don't search. I will choose the driver to install and click Next;
• Windows will show you the current driver that is installed for the modem. Click Have Disk, click on Browse to point to C:\USR\5637, choose the USR5637_II.inf file, click Open, click OK;
• Windows will show the selected driver: U.S. Robotics V.92 USB Modem II, clickNext to begin copying the necessary files to your hard drive, click Finish to move on;
• Repeat the above steps to update drivers for the U.S. Robotics V.92 USB Modem #3 modem;
• Now, Joyfax Broadcast can recognize all of your modems!