How to hardware-reset your DNS-323
There are 2 ways of hardware-resetting (or returning to factory defaults)
The hardware reset button is documented in the D-Link DNS-323 Manual ver 1.4. (http://files.dlink.com.au/products/DNS-323/REV_C/Manuals/v1.4/DNS-323_MANUAL_1.40.pdf) however does not discuss how it is used.
How-to perform a hardware reset
You can now use the EasySearch utility to search for your DNS-323. Note that EasySeach will only locate your device if you have left the name as dlink-xxxx, otherwise use a network IP-scanner to locate the device.
You device would have been reset to factory defaults, which would enable the DNS client utility as well.
Note: if you can not get the factory reset to work as described before, you may want to try first pressing the reset button and keeping it pressed while unplugging(basically inverting the first two steps)
Extra Note: for me the hardware reset is much more simple. Leave the 323 on and simply hold down the reset button for a few seconds. After a short time the square light on the front will start to flash. You can now release the reset button and you should be back to factory settings in a short while.
Addition to the Extra Note: I can confirm that this simpler method worked for me on a DNS-323, hardware version C1 and firmware version 1.10
On my version (H/W B1) the procedure is the following: when the NAS is on, press the reset button with a pin. Then, press the power button until it starts blinking. Then, release the reset button. Then, release the power button. This will go back to factory settings.