Magnus Dahl

if you cant log in by using 192.168.0.1 or 192.168.1.1 or even 192.168.100.1, yes, return it, it is not working properly i think

well, those are old cards, i was talking about new hardware, that i understood you bought, but you are right
 
at what channel are you using the 5ghz signal?  try 112

Wireless A and N run on 5Ghz. I thin N tops out at 450Mbps or at least that is what it’s rated to. I used to run an N900 wireless card that’s how I know. 

Not necessarily AC, just dual-band, ideally AC though.

This is what you have to discover. WiFi can work great for years, but a variable changes and your FUCKED. My guess is maybe someone added a Wireless router on the same channel as yours or something to that effect. Either way your probably getting some type of interference.  If your WiFi is actually disconnecting. 
 
Now as @goto10 suggested, you need to figure out. Is the WiFi actually dropping or is it your internet? Those are two separate things. 

change wifi channel on router
 
but remember that is not the same as wifi disconnecting than loosing internet access, you have to be sure what is the problem
 
wifi could be ok but internet could be having issues, be sure to know what is failing first

No problem, I may not be active on a regular basis, however this is one of the reasons why I am here, to help others.