*NOTE* At this point I was merely assuming, as I couldn’t fully verify my key as I wasn’t utilizing a VMAT server. The middle example of requiring the use of a retail key didn’t seem right, as I would assume any version would suffice. In my case I was using the proper image downloaded from VLSC with the key from the same web portal, So I knew I was good on the first and second examples. In the first example it makes sense, as well as the last one. E.G Attempting to activate a evail edition, or using a MAK key instead of a retail one, or using the wrong key with the wrong edition (Standard vs Datacenter). If you keep reading there are other potential reasons for activation to fail, but that usually happens afterwards with a dedicated error code. To my dismay I was greeted with a greeting, much like the thread poster: 'Can't activate Windows by phone.' Main thing I found was a command to get your started: slui 4 I found a couple guides to help along the way, and even a nice thread post. System is completely offline, how to activate it? Quick Story here, Installed a copy of Server 2019.
