First connect
APN- bsnlnet in your mobile with any mobile application.
Now on pc connect first bsnlwap in pc suit, it will not connect and u wiil get a message on mobile that u had used 0.00 kb.
Now put APN-bsnlnet in pc suit it will connect ...and browse and download for free...
only 1 or 2 paisa will be deducted in the last.
Note - for safty before starting any session on pc by bsnlnet ,once dont forget to connect via bsnlwap . and see the mobile screen that u have got the message that u have used 0.00 kb.