I assume u are asking for hyper terminal networking.
First of all, though obvious, you need to have a working modem with land line connections on both the pcs.
Next, start hyperterminal from Start->Run->Hypertrm on both the computers. Choose a name and an icon for ur conection. Fill in the connection setup. Save ur connection for future use. In one of the computers, enable "Call->Wait for a call". This computer will act as the called computer. In the other machine, go to "Call->Dial". Now you will be connected. You can type on the console which will be echoed on the other console. To send a file, go to Transfer->Send file.
Go to Transfer->"Receive file" and select the directory to save received files. Check the help if a bit lost.