As people ususally think, pressing the reset button isn't a hard reset. A hard reset is also called a 30/30/30 reset, and that's for a reason.
Performing a 30/30/30 reset is very simple. Though the results are generally the same as doing a normal 10 second press and hold, this is a 'harder' reset for the firmware, and not required always. To do it, follow these steps.
- Have the router plugged for power (duh!).
- Use a thin object to press the reset button, as you usually do.
- Hold the button for 30 seconds.
- While you hold the button, unplug the cable.
- Do not release the button. Hold it for 30 seconds with the power unplugged.
- Plug the cord back in, while holding the button.
- Hold the button for another 30 seconds with the power connected.
Update: I now know that you can even, in most cases, fix a bricked router using this technique.