Third party serial ports

Your seriously still using a serial port modem? For what?
There are usb to serail port adapters out there. I have a keyspan adapter that I use a work for an old telephone system.

I hear what you're saying. Unfortunately I am forced to use the serial port modem because the medical software we use in our office requires an antiquated modem for bill submissions. If I could chuck it out the window, I would.

I use Rosewill PCI serial port cards from Newegg. Don't use the USB to serial adapters.

Lava is also a good choice for serial port cards. Unfortunately, there is still a lot of DOS-based software out there in the medical community... so if the modem doesn't have DOS support, you're out of luck. Serial port external modems are usually guaranteed to work with DOS-based software. You still can find hardware-based internal modems as well that have their own COM port... but I haven't had the chance to see how well they work with DOS.