How do I setup a USB wifi adapter?

I purchased two of these adapters, with the intent to convert two laptops from 2.4GHz wireless g to 5GHz wireless ac.

Fast enough: I have 120Mbps service from my ISP, and once this adapter was up and running, speed tests show that it was able to achieve that speed most of the time. So, for a 120Mbps connection to the Internet, it's fast enough.

Too flashy: This adapter has a very bright blue LED on top that flashes slowly when it doesn't have a wireless connection, and flashes very rapidly when it does have a wireless connection. It flashes rapidly even when there is absolutely NO network activity. And the pattern of flashing isn't consistent...it looks like it speeds up and slows down randomly. At first, I had assumed the rapidly LED was a network activity indicator, and that the LED would be steady on with no activity, as is often the case for most network adapters I've used. So, when I saw all this constant/fluctuating flashing, even though I wasn't doing anything to generate any network activity, I thought perhaps there was some surreptitious transmissions going on. Scary. So, I shut down all processes that could possibly be talking on the network, fired up Task Manager, and fired up a network monitor. There was absolutely no network traffic, but this adapter was still flashing with a very fast and random pattern. I concluded that this is just how this adapter behaves, and have convinced myself that it's not tied in any way to actual network traffic. It's just trying to be annoying, but it's nothing that a little well-placed electrical tape can't overcome. (Suggestion to the manufacturer: Slow, steady flashing when it doesn't have a connection is fine. A connection with no activity should be on, with no flashing. Rapid flashing should indicate network activity.)

Odd MAC address behavior: When I got these adapters, I initially tested them both on the same laptop, just to make sure they worked. My router uses MAC filtering, so I have to record each adapter's MAC address and enter it into the router. I was surprised to see that both adapters reported the exact same MAC address 00:FF:FF:FF:FF:FF. My initial reaction was that I wouldn't be able to use two of these in the same network, because their MAC addresses would conflict. But after some experimentation, I realized that when either of these adapters is installed on another computer, it reports a different MAC address. I switched adapters on the other computer, and the new adapter had the same MAC address on that computer. So, the MAC address appears to be generated when you install the software for the adapter, and that MAC address is tied to the computer, not to the adapter. This is different from any network adapter I've ever worked with. Nevertheless, it meant that I was able to use both adapters in the same network.

UPDATE 6/14/2019: When I upgraded in-place from Windows 8.1 Pro to Windows 10 Pro, with this adapter attached before, during, and after the upgrade, the MAC address of the adapter changed. So, when I initially booted Windows 10 Pro, it couldn't connect to my router because the new MAC address didn't appear in the router's list of allowed MAC addresses. It was easy enough to change in the MAC Filtering section of the router, but this is another example of MAC address oddness with this adapter. Be aware that if you perform an OS upgrade, the MAC address of the adapter might change.

The adapter had some trouble reconnecting to a network that doesn't broadcast its SSID, even though it was set to connect even without the SSID broadcast. I had to keep reconnecting to the network manually. Once I changed the router to broadcast the SSID, the adapter consistently reconnected automatically without any intervention.

UPDATE 6/14/2019: Even with the SSID broadcast, the adapter has started to occasionally (twice a week, on average) lose the ability to see and connect to any wireless networks. The blue LED flashes slowly, and no available networks appear in the list. I can force the adapter out of this state by disabling and then reenabling the adapter in Control Panel | Network and Sharing Center | Change Adapter Settings. Once this is done, the adapter springs to life, sees its preferred wireless network, and connects automatically. The fact that this behavior started recently makes me think it's starting to fail. But it still seems to work, in spite of this occasional issue.

The software installation, on Windows 8.1 Pro and on Windows 7, required the included mini-CD-ROM. The included "manual" contains some conflicting information, but the software installation process worked, but was a bit klunky. There were several periods during installation when nothing appeared on the screen, even though the installation was still proceeding. At one point, while installing on Windows 7, the installation choked and reported the amusing message "Your local administrator is no longer working." Since I'm the local administrator, I almost took that as a cue to go on vacation. But instead, I rebooted, reinstalled, and all was well.

There doesn't appear to be any web-based support for downloads, troubleshooting, etc. I contacted the manufacturer, and they supplied links to an updated driver. The device shows up as a RealTek 8811CU 802.11ac NIC.

I'm not happy that I had to experiment to discover the MAC address behavior, I had to experiment to discover the true meaning of the constantly flashing LED, the documentation doesn't point to a web site with drivers and support (I contacted them through Amazon, and they then directed me to contact their sales email at inamax.cn), I had to set my SSID to broadcast to get the adapters to reconnect automatically, and the software installation was klunky. If it weren't for these issues, I would have given the product 5 stars.

But once I got beyond all that, the adapters do the job.

Update:

Radio Silence: A few days after posting this review, the adapter frequently and spontaneously entered into a state in which it couldn't see any networks at all. The LED flashed slowly, indicating no connection, and the list of available networks it saw was empty. This has happened at seemingly random times...it's connected and working just fine, and then suddenly drops the connection and can't see or reconnect to any wireless networks. The ipconfig command sees the adapter with the expected MAC address. Windows reports "no networks found" on this adapter. The included software shows that the radio in the adapter is turned on. I made sure that the router was working properly, that all other clients could see the expected wireless networks, and this was the ONLY adapter that has lost connectivity. (I've had this happen multiple times on both of the adapters I purchased.) There is no unusual interference in the area, nothing changed in the wireless network configuration when the problems occurred, and other wireless adapters used in the exact same location (e.g., same distance and direction from the router) see a strong signal and the expected wireless networks. It wasn't losing connectivity at all during the several days of using these adapters. Nothing changed in the router, network configuration, location of the adapter, or anything else.

To resolve the issue each time it occurred, I had to physically eject (through Safely Remove Hardware and Eject Media) and reinsert the adapter to get it to see any networks. When I do this, it almost immediately sees all the networks it should, and connects to the correct network. After this action, the connection might stay up for anywhere from 10 minutes to a day before getting back into this "radio silence" state again. Frustrating.

The seller worked with me through email to troubleshoot the problem, but was not able to resolve it. They issued a refund, and I will move on to find a different set of adapters.

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