Read this article and change some settings on your WDR4300. Your last two expectations cannot be fulfilled actually. http://www.tp-link.com/en/faq-573.html

WR841ND is a router instead of modem router. Do you have a modem work with it? Modem should be connected to WAN port of WR841ND. If it is correct, login web interface of WR841ND. Go to Quick Setup to...

If WLAN light is flashing, it means that Wi-Fi function is enabled. Any PC is connected to the router by network cable? Can you still access internet or login web interface of WR940N? If you cannot,...

None of them support shell access using telnet or SSH.

Did you login web management page of WA850RE with its domain name of IP address? After restart the router, login your router's configuration page and check the DHCP list. If WA850RE is listed, try to...

What's the speed of the wireless connection to the router on your laptop? There are some suggestions in the guide below. http://www.tp-link.com/en/faq-709.html