For example, I will update the firmware of the D-Link DCS-933L camera from version 1.10.13 to 1.12.03.
I will describe in steps:
1) Download the new firmware from the official site:
2) Open the settings by typing in the browser the address http://192.168.0.1 (maybe 192.168.1.1) and enter the login/password.
3) In the interface that opens, select “MAINTENANCE” – “Firmware Upgrade”, then click “Browse” and select the firmware file previously downloaded (unpacked from the downloaded archive), then click “Upload” to start the update process.
Wait for the update to complete, usually 2-5 minutes. At the end, the device will reboot.
Done. After updating the firmware settings remained unchanged.