A helpful link: http://www.tp-link.com/en/article/?faqid=384

The distance is so long. You need some powerful access point.

Is your case like this: http://forum.tp-link.com/showthread.php?1608-Beta-firmware-Solved-TL-WR1043ND-hang-up-with-high-bandwith-and-WEB-interface-dies&region=china ? Have you tried the above beta...

Test it on another computer if possible. if cannot work, contact the shop where you bought it to get a replacement.

If you connect PC to the TL-WR1042ND (WPA secured) by a lan cable, can you login TL-WR1042ND on your PC ? Can other wireless devices administrate the router ? Have you tried to upgrade the driver of...

A good link: http://www.tp-link.com/en/article/?id=227