Hi,

The TL-WPA4220 should be working properly cause the phone and laptop can pick up the signal and access internet. 

Regarding to the computer, what is the model number of the network USB adapter? 

Meanwhile, cause it does not pick up the signal of TP-Link, it is suggested to change some wifi settings of it, like the wifi name and wireless channel. 

Below is the instruction: download the utility first and then follow the instruction to change them.

https://www.tp-link.com/en/support/download/tl-wpa4220kit/v1/#Utility 

https://www.tp-link.com/en/support/faq/398/ 

Any updates, please let us know. 

Zxc wrote

I have a router on the ground floor and a TP link extender on the second floor (model "TL-WPA4220(UK)") I am on the first floor trying to connect my computer, MacBook and Galaxy s8 to the tp link. All three devices can see and connect to the router however the signal is too weak for reliable access, hence the extender.

 

When on the first floor sat in front of my computer, my phone and laptop can both pick up the tp link and have access to internet. My computer however doesn't. It can see my router and several neighbours routers / extenders, but not the one above me. We have moved the extender as close to my computer as possible without limiting it's range in other places.

 

I have also manually added the network to my computers 'Manage wireless networks' page (Windows 7), however, it doesn't even attempt to connect as it accepts the correct and incorrect password with the same response (I.e. no response).

 

My computer uses a tp link AC1300 high gain wireless dual band USB adapter. Currently there is insufficient infrastructure in place to facilitate an Ethernet connection. The TP link SSID is as far as I can tell unique to to the area and shouldn't cause any conflicts.

 

I'm out if ideas and wondered if anyone has any sugegstions as to what i may have missed? Thanks