Windows 2003 Support EOL:
What Data Science Tells Us

Two weeks from today, one of the most popular Windows server operating systems (OS) – Microsoft Windows Server 2003 – will reach its support end of life. After the Windows 2003 support EOL on July 14, 2015, Microsoft will no longer issue security updates or fixes for any version of Windows Server 2003.

OS vendors retiring old versions of operating systems is not new, but there is lot of press coverage about this impending event. Even the U.S. Department of Homeland Security issued an alert. I asked myself, “Is this really that significant or is Microsoft just leveraging this event to persuade their users to migrate to the Microsoft cloud?”

To better understand this, I worked with one of our data scientists to analyze the OS trends found in virtualized datacenters. Since 2012, CloudPhysics has been collecting a treasure trove of information from thousands of virtualized datacenters (vSphere environments) across the globe.

For this particular analysis, we examined the dataset collected between June 2013 and June 2015. We used relative ratios for all the data points. And we also used a first-order linear regression with a Gaussian estimator to create a model and used 95% confidence intervals for forward projections. For the impatient among us, here is the summary of the key findings:

7 Key Findings


One in every five Windows server VMs runs Microsoft Windows Server 2003, and thus will be impacted by the end of support life on July 2015.


The share of Windows Server 2012 VMs only recently surpassed Windows Server 2003 in May 2015.


Windows 2003 VM share is declining and, given the current rate of decline, will reach a statistically insignificant level in the first half of 2018 (about three years after the support July 2015 EOL date). This is a relatively faster decline compared to Windows 2000, which reached EOL in 2005 but retains 1% share 10 years later.


CloudPhysics does not have historical data prior to 2012, but our backward estimates indicate that the total number of 64-bit VMs surpassed the total number of 32-bit VMs in 2010. However, 32-bit VMs still persist and, given the current trend, will not reach statistically insignificant levels until the first half of 2018.


Windows Server 2012 VMs share will rise to 50% of Windows server VMs by the second half of 2018 – the same year Microsoft’s mainstream support for Windows Server 2012 will end.


The share of Windows desktop in virtualized datacenters is declining slowly. With the current projection, Windows desktop VMs will likely become statistically insignificant on vSphere platform by the second half of 2018.


VMware’s virtualization platform is prolonging the life of many legacy operating systems.

Source: CloudPhysics Global Dataset 2013 and 2015

The Detailed Analysis

It should be no surprise that Microsoft Windows is the dominant operating system in VMware virtualized infrastructures. According to our 2013 dataset, Microsoft Windows operating systems accounted for 70% (56% servers, 14% desktops) of the total number of VMs. However, in the last two years this number has dipped slightly down to 67%.

Interesting tidbit: The slight dip in overall Windows dominance is apparently due to the decline of Windows desktop VMs running on vSphere.

To take a closer look I plotted this trend and did a simple linear forward projection.

The grey band around each trend line indicates the confidence interval at 95%. It is typical for the confidence interval to widen as we project further into future due to increased uncertainty. With the current two year trend line, it looks like windows desktop VMs on vSphere will become statistically irrelevant by the end of 2018.

A Word about Windows Desktop VMs

I find this surprising, but there are few contributing factors to what this trend indicates:

  • Despite VMware’s continuous investment in VDI, desktops on vSphere haven’t really taken off due to the high storage cost associated with running desktop VMs on server class hardware.
  • The PC industry market overall is shrinking, along with Microsoft Windows share. Mac on the other hand is gaining market share.
  • Windows 7 wasn’t a huge success compared to Windows XP, which reached its extended end of support life period in April 2014.
  • More and more client computing is moving to the mobile platforms (e.g., iPads, tablets).
  • More and more apps are moving to the browser and the need for thick client applications is diminishing (even VMware’s own vSphere client is now a web browser application).

Trends for Windows Server VMs

Moving beyond desktops, now lets take a closer look at the trends with Windows Server VMs:

Within the Microsoft server category, Windows server 2008 is the popular OS right now but Windows Server 2008 share has dipped from 67% to 63%. Windows Server 2012 OS on the other hand has grown significantly from 2% to 19% and it seems that a bulk of the growth has come at the expense of Windows Server 2003.

Also interesting is the presence of trace amounts of legacy OSes (Windows NT, 2000 etc) that are more than a decade old. These OSes reached their end of support life long ago (see chart below) but we continue to see them. Likewise with Windows Server 2003: with end of support just weeks away one would expect its share to have gone down significantly, but that’s not the case. In fact, 18% – or roughly one of every five Windows server VMs – is still on Windows Server 2003 today.

OS End of Mainstream Support End of Extended Support
Windows NT December 2002 December 2004
Windows Server 2000 June 2005 July 2010
Windows Server 2003 July 2010 July 2015
Windows Server 2008 Jan 2015 Jan 2020
Windows Server 2012 Jan 2018 Jan 2023

Why do people continue to run legacy OSes on vSphere environments? The short answer is: because they can. For example:

  • Before virtualization, a server refresh generally required an OS refresh. Newer hardware platforms typically have limited or no support for legacy OSes so upgrading the OS became a necessity. With virtualization however the hardware and the OS is decoupled and therefore OS upgrades are not a necessity.
  • VMware announced support for 64-bit OSes in 2004 and the vSphere platform supports running both 32-bit and 64-bit OSes simultaneously. There is no need to choose one over the other, legacy 32-bit OS (and even 16-bit OS) can continue to coexist with newer 64-bit OSes.
  • VMware’s support for legacy OSes is excellent. It is possible to run a legacy OS like Windows NT on modern processors that Windows NT natively wouldn’t even recognize. Also the virtual devices in VMs provide encapsulation and prevent device driver compatibility issues.

A Closer Look at the Windows OS Decay

For additional insights on how the OSes are decaying, I plotted the trend lines and did forward projection. I plotted separate trends for 32-bit and 64-bit versions of the operating systems. Note: Windows Server 2000 comes only in 32-bit flavor and Windows Server 2012 comes only in 64-bit flavor. Windows 2003 comes in both 32-bit and 64-bit flavors.

Interesting tidbit: 32-bit Windows Server 2003 VMs share is declining 3x faster than that of the 64-bit version of Windows Server 2003.

I then combined the 32-bit and 64-bit server versions of Windows server VMs as plotted below.

Interesting tidbit: Windows Server 2012 VMs surpassed Windows 2003 just last month.

Further, looking ahead I expect Windows Server 2012 to rise to 50% share by the first half of 2018, which is the same year the mainstream support will end. And if history is of any indication of the future I don’t expect Windows Server 2003 VMs to disappear anytime soon. With the current projection, we predict (at 95% confidence) Windows Server 2003 won’t reach statistically insignificant levels until the first half of 2018.

Key Takeaways

Beyond providing some interesting factoids, our global dataset reveals that many organizations are or will be exposed to operational risks from running an OS beyond its support life period. This Computerweekly article gives a nice overview of the various risks associated with running Windows Server 2003 after the support period. The biggest risk is the lack of availability of security patches. OSes with substantial user bases generally become good targets for hackers, especially when they remain unpatched. That, combined with the projected prevalence of Windows Server 2003 VMs that will persist after the support period ends, suggests many organizations will be open to significant security risk. As Microsoft itself says, “If you are still running Windows Server 2003 in your datacenter, you need to take steps now to plan and execute a migration strategy to protect your infrastructure.”

So what are your options?

Microsoft’s Windows Server 2003 website has plethora of useful information to help you migrate applications away from Windows 2003. But before you dive into that process, the first step is to assess the scope of impact in your environment.

CloudPhysics can help you with the discovery process in a couple of ways:

  • CloudPhysics SaaS solution includes an OS inventory feature, which catalogs all OSes across your entire environment, across multiple vCenters. We have updated this feature so it now tracks end-of-support dates for all the Windows operating systems (and select Linux operating systems). With a few clicks you can quickly track down the VMs that are reaching (or have already reached) end of support life.
  • The OS inventory card is now available in our Free Edition for a limited time. It takes about 15 minutes to get our application up and running, so taking stock of your current Windows Server 2003 inventory is now fast and free. All you need is to sign up here.
  • As a part of your larger strategy, you may be considering moving some of your applications from Windows Server 2003 to the cloud. We have cost calculators to help you assess the cost of migrating to either Microsoft Azure Cloud or Amazon AWS.

Our mission at CloudPhysics is to discover discover hidden operational hazards. Clearly the analysis indicates that Windows Server 2003 is a potential hazard for many, and CloudPhysics wants to help you protect your organization from harm. Take 15 minutes today to make sure you’ve got your bases covered.

Helpful Links:

Windows Server 2003 end-of-life event

Risks of using Windows Server 2003 after the support period:

Department of Homeland security alert on Windows Server 2003:

Windows Desktop OS end of life:

Windows Server OS end of life:

Microsoft extends Windows XP support for special customers: (US Navy, UK Gov)