Your problem may be the hardware then if you are still unable to get it working going through the hardware manager and doing all the steps that steve.milner gave you above. If re-installing the drivers that were given to you with the machine and checking the BIOS settings still gives you the same outcome then the hardware would be the next suspect.

You may want the place where you got your computer to put a new modem in your laptop. I personally have had issues with Packard Bell products and have decided to not work with them any more because of the hardware issues that their machines poses. It wouldn't surprise me if the modem is not working.

Have a happy holidays and a fantastic new years - cheers
JP