Check your BIOS settings. If you have an internal modem and you are running thin on IRQ's, disable the external COM Ports in BIOS (do this anyway if you aren't using the external COM Ports on the back of your PC). On such a new BIOS, you should be able to configure modem settings in BIOS.
However, if not then after disabling the external COM Ports in BIOS, you might have to trick Win 98 into grabbing the the COM Port you desire by adding more than one modem in device manager, then deleting the bogus COM Ports/undesirable ones. After you got the Port and IRQ you want, select the modem and click the diagnostic test.
This may seem kinda crude, but it works for me when all else fails. Good luck!
<font color=purple><b>An average human brain weights aprox. 3lbs., but a thought weights a load.</font color=purple></b>