I know it's relatively simple but for the not so Tech savvy people:
Unlock your Huawei Modem for Free just drop your IMEI and your NCK.

huawei E173U-2
IMEI-860872017478729
Airtel modem

Unlock Code :33782920

CarlyX8:
huawei E173U-2
IMEI-860872017478729
Airtel modem

TechMax:
Unlock Code :33782920

thanks bro, which software will i use for the unlocking

Since you use an Airtel modem, just put another sim card that's not airtel,and connect to your computer.
A box will pop up asking you for the unlock code, put it in and you are good to go.

CarlyX8:

thanks bro, which software will i use for the unlocking

TechMax:
Since you use an Airtel modem, just put another sim card that's not airtel,and connect to your computer.
A box will pop up asking you for the unlock code, put it in and you are good to go.

not this modem oh!, it will just warn you and the interface will just close by itself.