Windows Server 2012R2 to Windows Server 2016

Businesses running Windows  Server 2008 or 2012R2 needs to upgrade to Windows Server 2016 or Windows Server 2019 because it is no longer supported by Microsoft.

What does it mean when Windows Server 2008/2012 is no longer supported by Microsoft?

  • You are at a higher risk of getting hacked or ransomware,
  • You are out of compliance with cyber security insurance providers, state or federal laws, FTC Safeguard Rules,  NIST framework, or ISO 27001 standards
  • You are not protected with the most current security updates because Microsoft stopped support in October 2023.

For more details, go here:

The Impending Threat: Windows Server 2012 R2 End of Support and Its Devastating Impact on Businesses Windows Server 2012 End of Support, Upgrade, Cyber Attacks


What are your options to upgrade from Windows 2012 R2?

The short answer is it depends! 

Why?  Because your business needs and requirements may be different from other businesses.

For example, if your current application is compatible with the latest Windows Server 2016/2019/2022, then you can upgrade.

In the following, we will assume your applications support Windows Server 2016 and your server hardware, such as Dell PowerEdge or HP ProLiant, is compatible with the Windows Server version.

NOTE: If you are running Windows Server Virtual Machine in HyperV or VMware ESXi, it can also be upgraded using the same process.

Alternatively, if your hardware/software does not support Windows 2016 or you don’t want to keep doing this in the future, we recommend migrating your applications to the cloud and using Azure Active Directory (AD) or Entra because it will keep your business more secure, updated to the latest version, and allows you to operate from anywhere.

Windows 2012R2 to Windows Server 2016  Domain Controller Upgrade

The following steps are an in-place upgrade from Windows 2012R2 to Windows 2016.  

Step 1 – Preparation (most important step)

a. If you are using remote access to install the upgrade, you will lose access during the installation.  Thus, you need out-of-band management like Dell iDRAC, HP iLO, Hyper-V or VMware console to the VM.  In addition, having a remote access tool such as Splashtop, TeamViewer, or LogMeIn is also recommended if you are working remotely.


b. You must have enough disk space on the C: drive and have 100 GB free or more.

c. Purchase the Windows Server open volume license for Standard or DataCenter edition that matches your current license.

d. Prepare Windows Server 2012R2 to support Windows 2016 Forest schema and domain schema, run the following commands:

  • Mount the Windows 2016 Server ISO or put the DVD on your server
  • Start Command Prompt in Admin mode
  • Go to Windows 2016 Disc (e.g., DVD drive R:) – run R:\support\adprep\adprep /forest prep
  • Press ‘C” to Confirm
  • It can take 10-20 mins depending on your environment and number of servers to complete
  • After it has succesfully complete the FOREST prep, run domain prep and repeat the steps like the Forest prep
  • run R:\support\adprep\adprep /domainprep


NOTE: If AD forest and domain prep commands successfully ran, you will get “ADprep successfully updated the domain-wide information” if you ran it again.

Windows Server 2016 ADPREP FOREST
Window Server 2016 Domain Prep Setup

Step 2 – Windows 2016 Upgrade

A. Run “setup.exe” file in Windows 2016 ISO or DVD

NOTE: If you are installing on a physical server, it will prompt you to enter your license key, otherwise you will need to activate the licnese later.

Select Window Server 2016 Standard (Desktop Experience) if your current is Standard Edition or select DataCenter if it’s your current version is that version.

If you do not select “Desktop Experience”, it will be the Core version and it will not have any GUI.

B. What Needs Your Attention
You will see the following message:

Windows Server upgrades are not recommended, for best results please clean install Windows Server 2016. If you must upgrade, before continuing make sure your app vendors support their applications on Windows Server 2016. Follow their specific recommendations before and after upgrade. For more information, go to Important: If the software isn’t compatible with Windows Server 2016 or if the app vendor doesn’t support the app, uninstall it before you install Windows. If you don’t uninstall the applications, your system won’t be supported, the app might not work, and settings or other information might be lost.


Microsoft will warn about the issues of upgrading and recommends doing a clean install.

And if ADprep/ Forest or ADprep /Domainprep was not ran, it reminds you to do it now before continue.

If you ran ADPrep commands as suggested above, try to REFRESH and CONFIRM

After you have confirmed, the installation will continue and upgrade domain controller and keep the Active Directory, DNS and application in place.

Your PC will restart several times.  This might take a while.



Step 3 – Verify the Window Server 2016 Upgrade

Next login to the server, verify all the services are running.

  • Confirm the C: drive has about 30% free space
  • Window Server 2016 is shown in SYSTEM (right click Start > System)
  • Or run SystemInfo in the command prompt to details of the server version
  • Check Services are running for the applications you use (e.g. if you have Duo Security, QuickBooks Database Manager).
  • Verify DNS, DHCP, Files Server and Printing services are running.
Windows Server 2016 Setup SystemInfo

Step 4 – Activation and Windows Update

Once you have confirmed that server is running and services are working, two important things to do are:
A. Active the software license
Go to Start > Settings > Activation.  Enter your license key.
B. Run Windows Updates

to install the latest Windows Server 2016 Build or Cumulative Update; it can take 1- 3 hours depending on your setup.

Windows 2016 Software Activation and Updates

If you remote desktop into the new Windows Server 2016  after the upgrade and get “an authentication error has occurred”, you need to update to the latest security patches.  Thus, you will require an out-of-band management tool or remote access software to connect and update before you can Remote Desktop in Windows Server 2016 as mentioned in Step 1 above.


You may find the following article are also helpful:

Contact eSudo if you need help or have questions about Window Sever Support option, We offer free consultation for company with 10+ people or more.

Frequently Asked Questions

eSudo is a local managed IT & Cybersecurity services (MSP/MSSP) company that helps businesses make technology seamlessly work over the last 22+ years in Silicon Valley. What sets eSudo apart is we focus on security first, and IT support happens to be part of the security services.

Our team of experienced and certified computer engineers understands that no two businesses are alike, that’s why we partner with our clients to develop efficient and cost effective computer networks, cloud solutions, network security, and phone solutions that help you run your business.

As a local Microsoft Partner and Cloud Technology Specialist, eSudo has the knowledge, skills, and commitment to help you implement modern technology solutions that match your exact business needs.

Our goal is to Keep your IT Systems running and data Secure (KISS) so you can focus on running your business safely!

We specialize in working with professional service organizations like law firms, accounting firms (CPAs), and wealth management. However, eSudo have helped other business such as non-profit organizations, manufacturing and other small businesses after we have reviewed their needs and determined if they are good fit for our services.

eSudo is not a traditional IT support company; we focus on security first, and IT support happens to be part of the security services.  In the dynamic landscape of network security, a proactive approach is key to safeguarding your business. It’s not a one-time event but an ongoing commitment to keep your systems resilient against evolving threats. With the rise of a mobile workforce and the omnipresence of phishing attempts or social engineering or AI, educating your employees, continuous monitoring and proactive support are vital to prevent data breaches.

If your business is looking for break-fix support or hourly IT services, we may not be for you because we cannot fully manage your risks and more importantly, it creates a trust issue in our relationship. Under a “break-fix” model, there is a fundamental conflict of interest between your business and eSudo.

“Over 97% of American businesses in 2023, operating in a digitally-driven landscape, heavily rely on the Internet for essential functions such as productivity, performance optimization, streamlined communication, bolstered sales, and various other facets of their daily operations. This heightened dependence on digital infrastructure, however, comes with a notable caveat: more than 87% of small businesses are entrusted with customer data that could be potentially compromised in the event of a cyberattack.”

We keep your IT Systems  running and data secure with our proven  IT Strategy, Managed Security, and Proactive Support & End User Management.  Our Strategy focuses on identifying, prioritizing, and recommending the right technology for your organization.  Our Managed Security includes data backup, device encryption, zero-trust access management, and policies & procedures. Our Support includes a live phone help desk, 24/7 monitoring, on-site support as needed, employee onboarding, and asset procurement. 

Click here to learn more.

  • Proven track record: We have been building our loyal customer base since 2001 in an industry where IT consulting firms come and go. Our customers, vendors, and employees stay with us because we build and value long term relationships with them. With operations all over the San Francisco Bay Area, eSudo provides reliable IT support to Northern CA-based businesses and beyond. We’re big enough to offer the facilities, services, and expertise you expect and small enough to provide the support and attention you deserve. 

  • People & Process:  Over the last 22+ years, we have created and adopted a proven process to ensure success in our operations and have trained our people to follow our proven process to provide consistent results for our customers.

  • Quality: We do not sell what we have not used or have tested. We recommend industrial and commercial-grade products for small businesses to provide uptime and reliability for our customers.

  • Responsiveness: A live person will answer your call, and emergency response time is one hour or less guaranteed. We use the most current remote support technology which lets us log in to your computers remotely to address many issues without the need to wait for a technician to come on-site.


Sue Lompico
Sue Lompico
eSudo has always been responsive and on time. They are knowledgeable
Ma. Guadalupe Garduno
Ma. Guadalupe Garduno
Excellent customer service, very diligent
I don't always write a review, but when I do.... it's a good one. Good partners in developing and supporting long-term performance, in-office and remote needs, cybersecurity safety and virtual workspace to take any office to the next level.
Matusich Raich Property MGMT
Matusich Raich Property MGMT
eSudo is always friendly, helpful, and quick to respond! They are always there when I need them!
Anirudh Muralidhar
Anirudh Muralidhar
Smooth interaction and support round the clock
Stacy Levy
Stacy Levy
Matthew was so helpful and patient: he untangled a multi- layered knots made by years of jury-rigged email systems. And he did it all with deep knowledge and good humor
Gwen Vasquez
Gwen Vasquez
Great customer service, fast response, always willing to help! Loved it!
Robert Liu
Robert Liu
There are hundreds of companies in Silicon Valley that offer computer support; it's a commodity service that every IT provider does for small business. What sets Matthew and his team at eSudo apart is they focus on security first, and IT support happens to be part of the security services. He helps small businesses like ours to keep systems up and running, ensure the data is available and the information accessible only by authorized individuals. If you are a small business owner or IT manager concerned with the security of your organization or need reliable, IT support, consider giving Matthew a call or message him.
Robbie Starks
Robbie Starks
Matthew and his team are fantastic. They are responsive, ask good questions, and make a strong effort to keep in touch when helping with IT issues. Would definitely recommend them to anyone shopping around for their business.
360Medical Supply
360Medical Supply
Very professional team. Will use again. Thanks.