What is the firmware version indeed? WA901ND has serveral operation modes like access point, repeater, client etc.. Which one are you using? Try soluction 2 in the instruction and upgrade firmware...

Access point or repeater? Do you know it is not necessary to connect hub and repeater by cable? http://www.tp-link.com/en/article/?faqid=250

Your firmware is not the latest version. Download the one, TL-WA850RE(UK)_V1_140826. http://uk.tp-link.com/support/download/?model=TL-WA850RE&version=V1#tbl_j After upgrade, reset and reconfigure it...

Lights are normal? Which firmware did you upgrade and how did you upgrade it? Can you hard reset it first? And then, check if there is iP address, default gateway obtained automatically on your PC?

Aleksey_R wrote Thanks for reply! Hardware version is "WR740N v4 00000000". At lest, this hardware version is displayed in 192.168.0.1. I didn't try to update the wireless driver on my laptop. My...

Kudos to your thread. Looks like quite complicated. Fortunately, I am NOT using a laptop with Intel 7260 wireless chipset.