Software Licensing – If You Can’t Prove It, You Don’t Own It – Part 2 – Windows Server

Sep 30, 2021 | Uncategorized

In Part 1 we covered the basics of licensing and specifically how it relates to Microsoft. This post we will go into more detail specific to the Windows Server family. At the time of the writing the only active Windows Server products on the market are the Windows Server 2012 R2 and Windows Server 2016 family of products. Since Microsoft changes the way they do licensing each time they release a new product this information only applies to these versions.

Server Licenses

Unlike Office or Windows 10 there are some more things that needed to be considered if you are buying a Microsoft server product, such as Windows Server 2012 R2 or Windows Server 2016:

  1. CALs
  2. Virtualization
  3. Cores

Server Licensing Scenarios We AREN’T Covering

Products like SQL Server 2016, SharePoint and Exchange are licensed differently from Server 2012 R2 and Server 2016. Since these are not likely to be found in most small to medium sized businesses these days we are not going to talk about them here. We are also going to ignore running Windows Server as a web server which has special licensing requirements (just to keep you on your licensing toes). If you have questions about any of these products or scenarios you are always welcome to contact us. We might revisit these scenarios later if we get enough interest in them.

Client Access Licenses (CALs)

You didn’t think once you bought an edition of Microsoft Server you could actually use it without further licensing, did you? Of course not! You have to pay for each person or each device (each client) that you want to allow access the server or use of some service the server provides. You only need 1 CAL per user or per device regardless of how many servers you actually have. When buying your CALs you should buy a few more (at least) than you currently need in order to allow for growth without having to go back and buy small numbers at higher prices.

Per User CAL

In this model, you buy a CAL for each USER (person) that is going to be using your system. This means each user that will need to log on to your network or access anything that is controlled by a Windows Server needs a CAL. User CALs are more expensive than device CALs, but usually end up more cost effective if you end up having way more devices than people.

Per Device CAL

In this model, you buy a CAL for each DEVICE that is going to be on your system. This includes all PCs, Macs, printers, wireless access points, etc. You would want to use this model if you have a lot more people than devices. So, if people share a computer (i.e. a call center with multiple shifts in a day) you would want to consider this option.


Thanks to the advent of multi-core processors, virtualization has now become commonplace. We’ve made a handy blog post talking about this here.

Server Editions (Pre-req to Cores)

Before we start into how cores affect licensing, we need to discuss various editions of Microsoft Windows Server. In the Server 2012/2016 world you have three basic editions: Essentials, Standard and Datacenter.

Server Essentials

This edition of server is designed for small offices that have 25 or less users and 50 or less devices. You can run it virtualized, but it is often deployed physically, and it is only valid for one instance of the operating system. This version of the server includes your CALs and is generally the cheapest version to deploy. There are some other restrictions in this version (such as the amount of RAM or number of cores it can use), so it is really only for the small business that isn’t planning on getting near the limits while the server is being used. The cost to migrate the server will eclipse the difference in cost between Essentials and Standard, plus you’d have to buy the Standard license (and CALs) when you upgrade, so if you think you might outgrow its restrictions within 3 or less years of purchase, you’d want to avoid this one.

Server Standard

This edition of the server is for either physical or small virtualized environments. Each license grants the use of the operating system twice on the same physical host in a virtualized environment. This edition does NOT include any CALs.

Server Datacenter

This edition is designed for highly virtualized environments. You actually license the physical host in this case and can use as many instances of the operating system on that host as you desire. There are some differences in the features of the Standard and Datacenter version of Server 2016, but there were none in 2012/2012 R2. You still need CALs for this version of server.

Buying a License

So, with all the above you might think you are ready to buy yourself a Windows Server license, right? Well, if you are going with Server Essentials you are ready to go, but for the other versions… Surprise! There are yet MORE things to consider. Now we’re ready to talk about cores in relation to licensing.

Windows Server 2012/2012 R2

In this version of Windows Server, you have to license the number of physical processors (aka sockets) in your server with a minimum buy of 2 processors. This applies to both Standard and Datacenter editions, regardless of whether the system is physical or virtual. So, if you have 1 or 2 processors in your server you buy 1 license of Standard or Datacenter. If you have 4 processors, then you would need 2 licenses of either (but you can’t mix and match). This is in addition to any CALs you might need.

Windows Server 2016

For Server 2016, Microsoft changed from per processor to per core, with a minimum buy of 16 cores. They have basically taken the per processor license cost and divided it so that each core 2-pack is 1/8 of the cost that the 2-processor pack was. So long as you have 16 or fewer cores in your system, the price is the same. If you have more cores than that, then the price increases. For Standard, each instance you buy has to be fully licensed. This wasn’t a big deal in Server 2012, as most servers that someone would consider buying and running Standard on only had 2 processors. With the shift to core licensing, that is no longer the case. So, if you need 4 virtual instances of Standard Server and you have a total of 20 cores in your physical server, then you would need 2, 20 core licenses.

Proving That You Are Licensed Correctly – Again

This part is important enough that we included it twice! Hang on to all documentation that relates to your licensing. Let’s say you’ve been careful and are actually licensed correctly. You still have to be able to prove it. So, if you bought Office from Dell when you bought your laptop, that means keeping that little piece of paper with the license key on it. If you bought a server license and CALs OEM or retail, then you should have some papers to prove it. It is really important you don’t lose these. If you buy your products volume licensed, then the licenses are tied to an email address. We recommend using a group address like “Licensing@[YourDomain].com” so that you don’t accidently lose access if an individual leaves the company. If you can’t prove you are licensed, then you aren’t.

I Can’t Even… I Had No Idea. This. Was. Confusing.

Yeah, we tried to tell you. If you just skipped to the end here in hopes of a concise write up, sorry, but I can’t get it much shorter than the above. Before you sign on the dotted line to buy your next server, make sure you ask the company selling it to you about the licensing and the CALs. Yes, this drives the price up, but it is cheaper than getting caught pirating the software.Confused or concerned? Have some questions about your licensing? Sawyer Solutions is here to answer any questions that you may have. Contact us.