Problem with TP-LINK TL-wn751nd signal range Windows 10

[Lucianoywea]

I live in a student house with like 16 other persons. There are 2 floors each one with a separated internet conection. Lets call them "Floor 1" and "Floor 2". First i bought a Wireless Wi-Fi card (TL-WN751ND) and i got like 2 bars of signal and a very unstable connection on Floor 2, but similar to Floor 1. Then i realized that my antena had a very weak reception (2dbi) and i bought a new one with 8dbi. The problem right now is that the signal has not improved with the new antena. Is the problem with my Wi-Fi card or antena?.
Here i put you some information that might be useful for solving my problem.

• 
  There are like 6 other people on the floor, I assume each one with a laptop and a smartphone connected to the Wi-Fi.
  A WiFi Analyzer screenshot, I'm in Channel 11. *The router is approximately 8 meters (26 ft) away.
  My smartphone and my laptop recieve good signal.
  I'm on Windows 10.
  Thanks everyone in advance for the anwers.

 

[Lutfij]

You mentioned the make and model of your wireless adapter but you've forgotten to mention the make and model of your wireless router as well as if the issue is the same across all the other 15 system's(assuming they all have one) in your dorm...?

If you're on Windows 10, your wifi adapter officially supports up to Windows 7. In this case try uninstalling your wifi adapters drivers and then reinstall it under compatibility mode:
Right click installer>Compatibility Tab>Windows 7 [from drop down menu]
and see if things change for you.

 

[schwatzz]

If you can access your router's settings, lock it down to use the 2.4GHz band only and set it to channel 1 wireless N only. If you are using 5GHz, you will get faster speeds but the signal won't travel as far or penetrate walls too well, so you signal will be weakened.