To receive landline phone calls on PC

Hi,
Can you guys tell me what software you use to receive landline calls on your PC?
I want to ans my incoming landline calls on my PC, which software you would recommend me for this? I don't want to spend money looking for a free software.

The Internet Protocol (IP) was originally designed for data networking. The success of IP in becoming a world standard for data networking has led to its adaption to voice networking.

There are three methods of connecting to a VoIP network:

* Using a VoIP telephone
* Using a "normal" telephone with a VoIP adapter
* Using a computer with speakers and a microphone

VoIP telephone calls can be placed either to other VoIP devices, or to normal telephones on the PSTN (Public Switched Telephone Network).

Calls from a VoIP device to a PSTN device are commonly called "PC-to-Phone" calls, even though the VoIP device may not be a PC.

Calls from a VoIP device to another VoIP device are commonly called "PC-to-PC" calls, even though neither device may be a PC.

Does the Modem have Talk/Speech capabilities ?? the make/model of the Modem would be helpful !

Can you guys tell me how to set up my pc & phone together?
I mean how can i attach my phone to PC?
Do I need to purchase any instrument for this?