How to Huawei E173Cs-1 Airtel India* E173z-1 MTN Sudan detect and unlock procedure

Unlock procedure will work on E173Cs-1 Airtel India and E173z-1 MTN Sudan modems with these firmware versions:
21.157.31.00.1043 (Build: Apr 23 2012 12:02:27)
21.157.31.00.284 (Build: Mar 17 2012 12:15:53)
21.157.13.00.284 (Build: Feb 16 2012 11:05:38)
Download firmware update  
Extract archive and launch Driver Setup .exe Click Start.

Wizard will detect modem and ask for firmware code.

Launch DC-Unlocker client software.

Open Server tab* enter your username and password that you received after credits purchase. Click Check login. (you can buy credits here www.dc-unlocker.com/buy)
If DC-Unlocker/Vygis/Rocker/Infinity dongle is connected* do not enter username and password* only click Check login.

Select manufacturer: Huawei modems* model: Huawei E303* proceed to Unlocking tab.

Select Generate Firmware code by IMEI.
Enter IMEI number.

Click Do job button.
Software will generate firmware code.

Enter generated firmware code to firmware update wizard and click OK button.

Wizard will start to update modem firmware. Do not disconnect modem or turn off computer – you can damage modem.

Remove SIM card from modem.
Launch DC-Unlocker client software.

Open Server tab* enter your username and password that you received after credits purchase. Click Check login. (you can buy credits here www.dc-unlocker.com/buy)
If DC-Unlocker/Vygis/Rocker/Infinity dongle is connected* do not enter username and password* only click Check login.

Select manufacturer: Huawei modems* model leave Auto detect (recommended) press Detect button (Big magnifying glass).

Wait till DC-Unlocker fully detects modem.

Open Unlock tab* select Read unlock code and auto enter to modem.
Click Do job.

Wait till you see a message that modem is unlocked.

After you see that unlock is successful* restart modem.