Go to the modems icon in Control panel and remove any modems 
that might be listed.

Go into your Bios menu by rebooting, upon bootup when it asks you to press 
a specific key (usually DEL) to enter Setup or Bios press it.
Go to Integrated Peripherals.
Make sure that Onboard Serial Port 1: reads something similar to 3F8/IRQ4
Make sure that Onboard Serial Port 2: reads Disabled.
Go to Chipset Features Setup and look on OnChip USB 
and USB  keyboard support. 
Make sure both of those are enabled. 
Go back to the main menu and go to the PCI/PNP Configuration menu.
Make sure that Reset configuration Data is set to enable. Save and Exit.

When the computer boots back up go to the Setup.exe file which was obtained 
From the website and run it.  The modem should now be installed under com3.
Com3 is the default com port of Windows NT registry for Non-Hardware 
Based modems.
 

If your modem is a jumpered ISA modem, then configure your jumpers for the com
Port and the the IRQ required.  Do not set it to plug N play because Windows NT is
not a plug N play system.  Go to the modems icon and have it search for a new modem.