Launch DC-Unlocker client

Detect device by selecting Huawei modems from manufacturers drop down menu list, leave Select model as auto detect (recommended) then click magnifying glass button

Wait till DC-Unlocker fully detects modem

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, only click " Check login "

Note: if you can't login or get error connecting to server after connecting Huawei E5170 to PC, check these settings here

Open Unlocking tab, click “Unlock”

Wait till you see a message that device was unlocked

After you see that device was successfully unlocked, restart it by disconnecting and connecting back. Now you can use it with any SIM card