WARNING Netgear WNDR4300 V1.0.1.42 FAULT
i suffered from this fault 
but managed to fix it when i saw this blog 
http://mikebeach.org/2013/08/15/qos-bug-in-netgear-wndr4300-v1-0-1-42-will-kill-your-internet-speed/
Basically the WNDR4300 QOS feature has a flaw in that the bandwidth detection is broken and so it reduces your internet speed to a quarter of what it should be.
You need to turn it off or enter a number manually.
Just posting this warning here in case anyone else has one of there routers.
but managed to fix it when i saw this blog http://mikebeach.org/2013/08/15/qos-bug-in-netgear-wndr4300-v1-0-1-42-will-kill-your-internet-speed/
Basically the WNDR4300 QOS feature has a flaw in that the bandwidth detection is broken and so it reduces your internet speed to a quarter of what it should be.
You need to turn it off or enter a number manually.
Just posting this warning here in case anyone else has one of there routers.