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Open your internet browser and enter the IP address in the navigation bar.
Aztech modem is quite cheap compare to other modem brand. I have been using for my home and office broadband connection. Usually the default password will be stated in the manual sheet enclosed in the modem box.
In case you misplaced it, then this might help.
IP Address: 192.168.1.1
Usually you can change the default user id and password to your own. This is important to stop other user or hacker to change it. So beware..especially when you use wireless network.