Performing a Netgear AC750 Extender factory reset will erase any custom settings you have made on the extender, and you will need to set it up again as if it were a new device.

To perform a factory reset on your Netgear AC750 extender, please follow these steps:

1. Locate the reset button on your extender. It is usually a small pinhole button located on the back or bottom of the device.

2. Take a paperclip or a similar thin object and press and hold the reset button for about 10 seconds. Make sure to press and hold the button until the Power LED on the extender starts blinking.

3. Release the reset button after the Power LED starts blinking. The extender will reboot and restore the factory default settings.

4. Wait for the extender to finish the reset process. This may take a few minutes.

5. Once the reset is complete, the extender will be restored to its factory default settings, including the default username and password.