The cloud revolution began in the Linux and Unix world, and for a long time the cloud wasn\u2019t a welcoming environment for workloads that run on Windows Server.\nEven today, not all cloud platforms are set up to handle the breadth of what can run on Windows Server. So what is the best public cloud service host for Windows Server? Should you choose Amazon Web Services, Google Cloud, Microsoft Azure or possibly another provider? Should you even run Windows Server in the cloud?\nTo help you answer those questions, I will take a look at the pros and cons of running Windows Server on each of these services, assess the rough costs for each choice, and suggest why you might want to choose one over the other \u2014 and why you might want to avoid some of them.\nAmazon Web Services EC2\nHaving basically kicked off the modern incarnation of cloud computing, Amazon Web Services (AWS) remains dominant today. AWS and its Elastic Compute Cloud (EC2) service power so many popular internet sites, whether as a data store, a video streaming service, host or content delivery network partner, that you could say the internet today is plumbed with Amazon services. Naturally, the many shops that already have their Linux and service workloads on EC2 are going to think of it when they consider putting Windows Server in the cloud.\nFor the most part, EC2 will accommodate them. In fact, Amazon seems to be willing to run Windows Server in certain workloads that Microsoft itself, via its Azure hosting service, will not support. Exchange is one example.\nMicrosoft will not support running Exchange Server on Azure virtual machines. This could be because Microsoft knows Azure is unable to measure up in certain ways to the ideal Exchange performance profile, or (more likely) Microsoft wants your cloud Exchange deployment to be done with Office 365 and Exchange Online rather than by just turning up a bunch of virtual machines in Azure and duplicating your existing data center.\nAmazon seems to think there is no performance problem with its cloud storage engine, and it fully supports running an Exchange Server deployment in production right on AWS EC2. It even boasts about a whitepaper and fully configured solutions available from partners right in the EC2 marketplace. Amazon\u2019s confidence could derive from its status as the granddaddy of cloud computing: Its storage infrastructure is simply more mature, or perhaps it has better-performing hardware options readily available in all of its regions.\nTo run Windows Server on EC2, you have two options. You can launch EC2 dedicated instances \u2014 you essentially deploy a copy of your existing workload on EC2 as if you were importing a virtual machine, license intact, to the service. The second option is to launch EC2 instances of Windows Server as needed. In that case, you would need some sort of provisioning to continuously set up the environment the way your workload dictates.\nDepending on the hardware you include in the instance, general-purpose EC2 instances range from $0.0082 per hour all the way up to $6.471 per hour. To optimize for storage or compute performance, you\u2019ll pay two to three times as much. This includes the cost of the license. Dedicated instances entirely depend on your region and require you to bring your own license.\nGoogle Compute Engine\nGoogle is by most measuresNo. 3 among the major cloud providers, although it certainly has big dreams, and a ton of money to make those dreams come true. Some of that money is clearly going toward discounting \u2014 Google claims that its \u201ccustomer-friendly pricing is on average 60% less for many compute workloads compared to other cloud providers.\u201d I might quibble with 60%, but Google definitely charges less.\nGoogle is rather famously a Linux shop, and Compute Engine, the infrastructure-as-a-service component of Google Cloud Platform, didn\u2019t support Windows at all until July 2015, when it began offering support for Windows Server 2008 R2. It now supports running later versions, as well as Exchange and SharePoint Server. Overall, it seems as if Google is playing catch-up in the cloud. Things could change, if its ambition matches its bankroll, but for now Compute Engine is much more attractive for Linux workloads than for Windows.\nThe fact that it is bargain-basement cheap for a lot of scenarios and supports license mobility could start to make a difference in the standings, but I cannot imagine many instances where traditional Windows Server workloads belong in Compute Engine.\nGoogle Cloud has Windows Server public images that start at 2 cents per hour (a price that includes just the license cost and not the cost of the compute hardware), up to 16 cents per hour for four core machines on a standard machine type. One thing Google does pretty well is metered billing to the minute, as opposed to paying by the full hour.\nFor shops that have the tightest of budgets and that don\u2019t really care about anything but running VMs in the cloud, Google could be a wise choice.\nMicrosoft Azure\nObviously, Microsoft would have you believe that running Windows Server \u2014 any flavor, all the way back to Windows Server 2008 R2 \u2014 on Microsoft Azure is basically the best of all worlds. The hypervisor used in Azure is the same Hyper-V that is bundled within Windows Server; Azure itself runs on Windows Server for almost all functions; and in general, no one knows how to engineer a cloud service to run Windows Server better than Microsoft. Or so the theory goes, and from my experience, it\u2019s true.\nAnd the all-Microsoft nature of running Windows Server in Azure does result in some interesting features:\n\nIt is simple to flip VMs into Azure and back again. Since VHDX files for hard drives are interchangeable between the services, all you need is a decent enough transmission speed between your location and the Azure data center closest to you to move VMs back and forth. This interplay is, as far as I can tell, unique to Microsoft Azure and one of the core reasons to choose Azure over another public cloud for those workloads where portability is important. You can import into AWS, but not directly \u2014 you must go through a conversion process.\nMicrosoft will give you credit for the Windows Server licenses for which you have already paid. Most other cloud providers must include the cost of the runtime license for the operating system in their compute rates, but customers who have purchased Software Assurance with their Windows Server licenses can get access to cheaper compute rates on Azure that only take into account the cost of the hardware resources. The price nets out the cost of the license, which is nice for shops with significant investments in Windows Server.\nIf you want to permanently move workloads into Microsoft Azure, then you can move your Windows Server Standard or Datacenter licenses with Software Assurance permanently to Azure via the Azure Hybrid Use Benefit. The pricing you get and what you save depends on what kind of Azure agreement you have, but a rough rule of thumb is to price out a VM equipped identically to your Windows workload but that runs Linux, which of course does not have a licensing cost component.\nDid you know that there is a Windows Server version that runs on ARM processors? There is, and it\u2019s for Azure only. But if you are geeky enough to want your instances to run on those processors, it doesn\u2019t seem that you can choose that to happen at will. As Mary Branscombe recently reported in CIO, \u201cMicrosoft has ported only enough of Windows Server and those associated software components to run the workloads for which ARM is a good fit. While [Microsoft Distinguished Engineer Leendert van Doorn] showed that code at the Open Compute Platform Summit earlier this month and confirmed that several Microsoft cloud services will use ARM servers, van Doorn also made it clear that this ARM version of Windows Server is for internal use only.\u201d\nI have found that, setting aside the hybrid use benefit Azure allows, running Windows Server on Amazon is slightly cheaper than on Microsoft Azure. Google Cloud has been cheaper still, but they have referred to their current pricing in ambiguous ways, leading one to conclude that it is introductory and will rise. Prices of course differ based on volume, configuration, discounts and more, but these are general observations.\n\nOther cloud providers\nDo you want to avoid the Big Three, in the hope that you will get better, more customized support from a smaller shop? That might be possible, but let me offer a huge caveat: I do not see a path to business viability for the smaller cloud players in the next five to ten years.\nEach of the Big Three cloud providers is spending billions upon billions tricking out new data centers with the latest hardware and networking technology, and they all have the deep pockets required to build out a cloud platform at a global scale.\nIt\u2019s just not realistic to expect a smaller provider such as Rackspace to match Microsoft\u2019s and Amazon\u2019s hardware spend dollar for dollar. Nor can the smaller players match the volume (and attendant discounted pricing) that the Big Three offer OEMs.\nTo boil it down into one point: Right now, Microsoft is limited only by the amount of power it can get delivered into its sprawling data centers, and not by its ability to fill it with hardware. Electricity is the hang-up.\nBecause the Big Three are so well-funded and committed to the cloud approach, this entire market is going to be a race to the bottom: The major competitors will be able to price out any newcomers or existing smaller players in the market, and as the Big Three\u2019s services improve and become more capable, the smaller players are going to find it increasingly difficult to carve out any sort of competitive advantage \u2014 and eventually it will simply be infeasible.\nSo I would avoid making long-term plans to run Windows Server workloads on smaller cloud providers. Sure, take advantage of them while they are around, but don\u2019t build a business model around them. Their days are numbered.\nYour choice depends on your needs\nThe cloud wars are making it cheap to run Windows Server on someone else\u2019s hardware, with no upfront investment. That\u2019s great news for everyone other than the smaller cloud providers that are likely to get squeezed out.\nOther than avoiding those smaller players in the long term, which of the cloud providers is your best bet for hosting your Windows Server workloads? It really comes down to what is most important to your organization. Google Compute Engine is the cheapest right now, but AWS has the cloud expertise, and Microsoft, naturally, can\u2019t be topped in Windows Server know-how.