[img]http://1.bp..com/-nGfcX4dx5cM/VZe6Qu8gteI/AAAAAAAABRg/yzDaCHuvnL8/s1600/unlock-huawei-303h1.jpg[/img]Most times, unlocking (aka cracking) Huawei 303s modems in general is not child's play especially if you are using the wrong software or employing the wrong method. Though it is not free, there is a sure-fire way to unlock these modems (303H to be precise). Before we start here are the list of Huawei 303H modem versions, builds and Internet Service Providers that's using them.
ISP VERSION BUILD
Airtel Nigeria 21.318.25.00.408 Feb 22 2014 11:03:06
Tigo Tanzania 21.318.25.00.787 Apr 15 2014 13:55:03
Cameroon Orange 21.318.15.01.314 Mar 7 2014 15:25:48
Entel Bolivia 21.318.25.00.279
Cape Verde Unitel t+ 21.318.25.00.1222 Mar 6 2014 12:58:56
Airtel India 21.318.25.01.284 Mar 4 2014 19:57:12
Airtel India 21.318.15.01.284 Nov 27 2013 09:20:10[b]DISCLAIMER:[/b] Though this operation is fool proof under normal circumstances, but by following the steps on this page, you are agreeing to be responsible for the end result of this operation, be it good or bad.
1. Buying the Unlocking Credit
The first step you have to take is to buy credit. Go to https://www.dc-unlocker.com/buy, choose the payment method that is convenient for you and fill out the form with the required information.

Beside the Credits textbox click on How much do I need? to find out how much you need for unlocking the modem. As at the time of publishing this post, it was still €1. Enter the required amount in the Credits textbox click on the Confirm button.
2. How to Unlock/Crack Huawei 303H Modem
After you're done with the payment and it has been processed, download Huawei HiSilicon Firmware Writer, insert an alien SIM (i.e. SIM of another ISP) inside the modem and insert the modem into a USB port. Remember to close the modem software if it auto-starts.

Run the Huawei HiSilicon Firmware Writer.

Now, the computer needs to be connected to the internet. You can use a none-Huawei modem (e.g. ZTE) or Wi-Fi connection to put the computer online. Login to with your username and password (if you're a new user, check your email address for the password).

After a successful login, the software will automatically detect and read the modem.

[img]http://2.bp..com/-1kvae4vowKQ/VZe6Q1VUcdI/AAAAAAAABRo/DXkcZrorPYk/s1600/unlock-huawei-303h2.jpg[/img]Click on Enter support area button and from the open webpage, navigate to Firmwares > Huawei > HiSilicon_platform > E303 >E303H_Not_locked_Firmware and download the .dgtk file. When you're done downloading it, go back to the firmware writer and under Firmware file click on the white paper icon on the text box.
Navigate to the location of the downloaded firmware file, select it and click Open. Remember to change the Files of type : to Digiteka files (*.dgtk), else you won't see the firmware file.

After this, you have to click on the Update button. This will trigger the processes of rewriting the modem firmware.

[img]http://4.bp..com/-D-TUkuJMl1U/VZe6Q_jzTTI/AAAAAAAABRk/UUTHZHZ3Pkc/s1600/unlock-huawei-303h3.jpg[/img] After a successful unlocking, you should see this: [img]http://4.bp..com/-hsakQoO1U6s/VZe6RUhV24I/AAAAAAAABRs/1dypAMaZUy8/s1600/unlock-huawei-303h4.jpg[/img]

Congratulations! You have successfully cracked the modem.
3. Creating Connection Profiles
The final step is to create connections profiles for the alien (now supported) SIM. Depending on the interface of the modem software, navigate to Tools > Settings and click on Add to enter the appropriate values.

Below is the connection details of Nigerian ISPs, if you're not in Nigeria, I'll advice that you check the web for settings that is related to the ISP you're using.


MTN NIGERIA
Profile Name: MTN NG
APN: web.gprs.mtnnigeria.net
IP or Proxy Address: 010.199.212.002
Port: 8080


GLO
Profile Name: GLO NG
APN: glosecure
IP or Proxy Address: 010.100.098.022
Port: 8080


AIRTEL
Profile Name: AIRTEL NG
APN: internet.ng.zain.com
IP or Proxy Address: 172.018.254.005
Port: 8080


ETISALAT
Profile Name: ETISALAT NG
APN: etisalat
IP or Proxy Address: 010.071.170.005
Port: 8080 Cheers!

Source:Wilburtech.com