You should consult your router's technical support. :D

Channel width can be modified to 40MHz on C7? You'd better secure the network with WPA2-PSK, AES. What's the speed you get with your old N router? Did you test wird speed to C7?

Did you read notes on their website before upgrade? You can restore it to facotry defaults and reconfigure it to solve it. Note:Since the security mechanism of the new firmware have improved,the...

You can access internet on the PC connected to LAN port of TL-WR1043ND? Any WAN IP address on its web interface? Did you try to upgrade it, reset it to factory defaults and reconfigure it?

192.168.1.129 is your PC's IP which should not be limited? If so, it should be excluded in IP range.

Yours is WR1042 or WR1043? Did you try latest firmware? By the way, are you testing speed by wire or wirelessly connected to router? If you are using speedtest, check the download speed when...