That's what I had to do recently as well and it worked.
Tips:
1. Hold reset down on the camera for at least 10 seconds
2. As Tony says, make sure the camera is connected direct to the pc ie if using dual NIC's, plug the camera into the LAN connection as Config may not see it in the second network card. Ignore any error saying you cannot configure the cameras over LAN. The software is seeing a LAN but in reality the cameras are connected directly.
3. Next to the search icon in the config tool there's a setting icon. You may need to click on this and enter in an IP range to search - if resetting use: 192.168.1.108 - 192.168.1.109 for Dahua as .108 is the standard address. Enter your password as well into the relevent field (manually do NOT cut and paste it in!!! - my big issue), then re-search. Your camera should then show in the search results and you can change the IP / intialise it and reconfigure it from there by checking the box next to it.
4. Write your in camera settings - image etc down before resetting your camera (useless here if you can't contact it atm) but good tip to do before this situation happens - write or screenshot them once you've set the camera up so you have them to re-enter if in this situation where you need to re-set your camera.