Do you want to monitor bandwidth or Track Net Usage
SO HERE IS A SOFTWARE FOR YOU
IT is called as Shalplus Bandwidth Meter.
You can use this software to track your net usage automatically. Most often people who are not in unlimited plans, used to checkout the service provider sites, That is not needed ofcourse, Now here is a solution..just download this small software which is less than 500 KB and use this to track your net usage.