1. 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
(firmware code = old flash code)
Flash codeCalculator here
2. Download Huawei Code Writer( here is a software that write unlock codes to your modem and unlocks ... modems that do not ask for unlock code but are locked or says Incorrect Sim Card.)
3. use unlock code= new huawei algo code
