Once you have Airtel Live activated on your airtel number then we are good to move ahead.
To get free airtel internet you need to use a web-browser Tea-shark.
Tea shark mobile browser is a cool software which work on Java enabled handset.
Download Tea-shark from there official website or you can point to wap.teashark.com on your handset and can download this software directly on your mobile.
Once installed you can start surfing with Tea shark browser.
In case if it ask for GPRS settings point it to Airtel Live.
This trick is working for almost everyone.
But I will suggest you to cross check your balance after few minutes of surfing.