Download factory image WNDR3700v4-V1.0.1.32 from netgear web site
Flash back via TFTP method
http://forum1.netgear.com/showthread.php?t=53239
– plug the PC into LAN port 1
– set the pc to a static IP of 192.168.1.2
– power on the router
– press and hold the RESET button as soon as the switch LEDs light up.
– keep holding RESET until the power LED begins to flash orange and then green.
– only the power LED is flashing green (and of course port 1), release RESET and than
-tftp -i -v 192.168.1.1 PUT <filename>