All u have to do is to follow these step properly...

You need a PC or a Laptop and the required connectivity tools ,ie.,

Serial/USB cable OR Infrared Device OR Bluetooth dongle

1) Activate Airtel Live! ( It's FREE so no probs)

2) Create TWO Airtel gprs data accounts (yep TWO) and select the FIRST

as the active profile.

3) Connect your mobile to the PC (or Laptop) and install the driver for

your mobile's modem.

4) Create a new dial-up connection using the NEW CONNECTION WIZARD as

follows

Connecting Device : Your mobile's modem

ISP Name : Airtel (or anything you like)

Phone Number : *99***2#

Username and Password : blank

You need to enter a special modem initialisation string of:
+CGDCONT =1,"IP","apn.address" - you should substitute apn.address with the name of the GPRS APN that you wish to connect to