I've been using, repairing, and building computers for nearly 30 years. A while back I went looking for a wireless because of a computer I'm assembling. I read many of the reviews you see here and of course had to wonder if I should add this to my cart. Well I'm on the side of WOW! and I'm glad I did.
I connected this in place of an Intel Centrino and it's not even good competition. I tried it on my Asus with an Atheros card and a Dell with a Dell card and the same results. All are running Win 7 although two are new machines I don't choose to use 8 on.
But hardware works the same when using different operating systems, they just install differently and 8 or 8.1 should be the same, so do this. Just open your wireless connections up, plug it in and wait 30 seconds for the driver to install, you'll see network 2 appear and then choose your new connection, then disconnect from your previous connection. That's it!
I had purchased a $50 extender to try and improve my download speed but this works much better without the extender, I have no use for it anymore. My second closest neighbor is 400 yards from me and I'm picking up 19 new networks! They must be ¼ mile away at least!
Needless to say I'm thrilled and recommend this. I can only assume the negative reviews came from those who have problems connecting computer equipment or received that occasional lemon. But I also see they are trying too hard, Windows has all you need and so don't install any software. For Windows just do what I did and 50 seconds after plugging it in you'll be looking for your network among the 3 times as many as you had before and if that's not enough, get a USB extender cable and raise it up higher.
For those unfortunates who say they see no improvement, I want to scream. YOU NEED TO DISCONNECT FROM YOUR OTHER CONNECTION!!! If only they could hear how loud I typed that. This happened to me twice before I correctly configured the old card to be secondary on the computer network, otherwise at times it would choose to use the old card and network.
I'm writing this because I was so unsure if this was what I wanted after reading the reviews. If you've read this, now you know and you know how to install it in Windows and you'll know I'll send this to Amazon through 5 walls, 50 feet from my router at wired speed, no sweat. I'm just here to help.
Connecting this to the sixth computer, I had a different experience. It was shown in connections but when I entered the passcode it said it was wrong. So I searched for and found the wireless driver at Mediatek.com-menu-downloads-USB wireless and all is well.