Limiting my Airtel ADSL Broadband speed to 512kbps.

[deba]

Dear All,

Kindly let me know whether there is any free software available to limit my Airtel ADSL Broadband speed to 512kbps. I am using the 4Mbps plan with 80GB FUP in Kolkata. Please note that I do not want to toggle with the configuration page of my modem hence I am looking for free software for Windows 7 and 8.1 to control my bandwidth.

Thank you.