Use my PC as an Extension Phone
 

I would like to use my mike and speakers on my Vista laptop as an extension phone (another house phone) to dial and receive voice calls. I am not looking for an internet service just a way of creating a working phone using my existing home phone service.

If you have a dial up modem installed on your pc then you need to connect this to a phone jack at your home. This cannot be done wirelessly so don't even go there
One you have the computer connected to the phone jack you will need set up a fax and phone software that usually comes with the modem. Insert your information and check to see if the mike and stuff works...there is a built in phone dial that you will have to use with the software. A regular number pad will not work on it!