In that case, contact TP-LINK support to ask for the chip of the adapter. Then, you may go to the website of chip manufacture to download the proper driver for Linux.

A little confused by your description " but I don't have an admin password for this computer" You may refer to the following link to login to it. http://www.tp-link.com/en/article/?faqid=174

:confused:Change MAC address of your PC??? or ....

Try to change another wireless channel on your wireless router.

A little confused. since you need to set up repeater, the wireless security type & channel should be the same with original wireless network you may refer to the following link to check the settings....

As I know, there are several working modes on TL-WA701ND. Not sure yours, so it's inconvenient to find out the problem.