The main problems.

The most problematic issues I have had with this adapter so far is the fact the connectivity is so-so if you could say.
Whenever using my adapter (In both a USB 2.0 and 3.0 slot directly connected to the motherboard) there will be countless connection failures both to my main Router (being SKY) and the "TP-LINK" wifi extender. If I do manage to somehow get lucky enough in which this adapter will finally connect another problem will arise. Slow speed, when I say slow speed I am not talking about 100mbps out of whatever my highest possibility is, I mean downright slow. This adapter, when it wants to for some reason or like I previously stated, when i get lucky, will manage to pull the speed it can find up to 140-160mbps Min to max. But lately my speed has plummeted to a measly 20mbps. And that is not all, from here my connection speed will slowly but surely drop, 20 to 15 in under a minute, and will continue to do so until ultimately it will just disconnect me from wherever I have decided to connect to. I do not use a laptop, instead a desktop. So my only real possibilities of connection, are home connections.

I am not a tech person as annoying/complicated this may make things for anyone that decides to help, but if you can guide me on where to go I will comply. 

I should also note, despite all the drivers I download and use, this problem still persists. I have turned of the feature for windows to disable my adapter for power saving and still no luck. The light on my adapter is a solid green, no flash. And I am more than aware my adapter can do so much more better given the past higher speeds.

I would appreciate any help a technical support agent may offer as-well as anything from the community. 

Please and thank you.

P.S- Just a reminder I absolutely SUCK at computers so if you do decide to assist and midway through writing think to yourself "Will they even know what I am talking about?" (Which I probably won't) I will take no offense in you "dumb-ing" it down if you will for me. I just wish my internet speed can reach the peak it once arose to and continue to use my PC to its full extent.