Which one cannot be logged in? D7 or WR940N(RT)? When you cannot login, can you ping its IP address successfully? Upgrade latest firmware, reset the router to factory defaults and reconfigure it.

Follow the guide below to check your configuration. If it won't help, submit a ticket to report the problem. http://www.tp-link.com/en/faq-444.html http://ticket.tp-link.com/index.php?/Tickets/Submit

WPS510U has no USB storage function. You are talking about PS310U, right? Unfortunately, it has no such a feature. You have to use the storage software. Some TP-LINK routers with storage sharing...

PS310U has no such a feature. Some TP-LINK routers with storage sharing function can allow users to access the USB drive via IP address.

No THX~ :) I just share something I tried but I don't know why...lol Did you secure the network again to see it works as well?

There is a newer firmware than yours. Give a try. http://www.tp-link.com/en/download/Archer-C9_V1.html#Firmware