Sending Fax With Win98

I have win98 se, win xp and win 2000 installed on my computers.
I was unable to send fax from any of the operating system.
To send a fax does the fax modem is required ?
I have Dlink 56000Kbps external modem.
Can you give me a step by step installation.

At other network where i have internet connection at the lan switch and no modem is connected to any specific computer. The third party software doesn’t detect the modem after installation.

Please help me
name some of the third partywoftware
thanks