You Just Installed Windows Server 2022 and the Clock Is Ticking
You’ve finished setting up your new Windows Server 2022 instance. The roles are configured, the services are running, and everything seems perfect. Then, a notification appears in the lower right corner of your screen: “Your evaluation period will expire in X days.” A wave of panic hits. Is all your work about to be locked out? Do you need to rush a purchase order through finance immediately?
This scenario is incredibly common for administrators, developers, and IT pros who use the evaluation version of Windows Server. Whether you’re testing a new feature, building a proof-of-concept lab, or waiting for final licensing approval, that expiration timer can feel like a looming deadline. Fortunately, Microsoft provides a built-in safety valve, a process known as “rearming.”
Understanding how to rearm Windows Server 2022 is a crucial skill for anyone working in non-production environments. It allows you to legally extend the evaluation period, giving you more time to complete your testing without interruption. This guide will walk you through exactly what rearming means, how to do it correctly, and what you need to know to manage your server’s grace period effectively.
What Does “Rearming” Windows Server Actually Do?
Before diving into the commands, it’s important to understand the mechanism at play. When you install Windows Server 2022 Evaluation, it is activated with a generic evaluation product key. This activation starts a 180-day timer. Rearming the server resets this specific timer—the Windows Software Licensing Manager component—back to its initial state.
Think of it like a stopwatch. The evaluation period is a 180-minute countdown. Rearming doesn’t change the length of the countdown; it simply resets the stopwatch to 180 minutes again. The server itself, your data, configurations, and installed applications remain completely untouched. It’s a licensing operation, not a system reset.
It’s also vital to know the limits. Microsoft officially permits you to rearm a Windows Server evaluation installation up to six times. This means you can theoretically extend the usable evaluation period to a maximum of 180 days multiplied by six, plus the original 180 days. In practice, the total possible evaluation time is 180 days for the initial period, plus up to 180 days for each rearm, culminating in a potential total of 1,260 days (or about 3.5 years) of evaluation use. However, you must perform each rearm before the current timer expires.
The Prerequisites for a Successful Rearm
You cannot rearm a server at any time. A few conditions must be met, and checking them first will save you from errors.
First, you must be logged into the server with administrative privileges. Standard user accounts lack the permissions to modify licensing components. Second, the server must still be within its active evaluation period. Once the evaluation expires and the server enters the out-of-grace shutdown state, the rearm option is no longer available. You must act before the timer hits zero.
Finally, ensure you have not exhausted your rearm count. You can check this before attempting the operation. Also, while not always required, it’s a good practice to create a system restore point or have a recent backup. This is not because rearming is dangerous to your data—it isn’t—but because it’s a good general rule before making system-level changes.
Step-by-Step Guide to Rearm Windows Server 2022
The primary tool for rearming is the Software Licensing Manager command-line utility, slmgr.vbs. This Visual Basic script is built into Windows and is your direct interface to the licensing subsystem.
Checking Your Current Evaluation Status
Before you change anything, you need to know where you stand. Open an elevated Command Prompt or Windows PowerShell session. Right-click the Start button and select “Terminal (Admin)” or “Command Prompt (Admin).”
To see the detailed licensing information, including the expiration date and the remaining rearm count, run the following command:
slmgr.vbs /dlv
This command displays the detailed license information in a new window. Look for the “License Status” line. It should say “Licensed” or “Initial grace period.” More importantly, find the “Time-based activation expiration” or “Evaluation expiration” date. This is your deadline. Also, note the “Rearm count remaining” value. If it shows 0, you cannot rearm again.
Executing the Rearm Command
If your status check confirms you have time left and rearms available, you can proceed. In the same elevated command-line window, execute the rearm command:
slmgr.vbs /rearm
You will see a message stating, “Command completed successfully. Please restart the computer for the changes to take effect.” This is a mandatory step. The licensing changes are staged but not applied until the system reboots.
Go ahead and restart your server. You can do this from the command line with shutdown /r /t 0 or through the Start menu. After the server boots up, the evaluation timer has been reset. To confirm, run the status check command again:
slmgr.vbs /dlv
You should now see a new, future expiration date—roughly 180 days from the moment of rearm—and the “Rearm count remaining” value will have decreased by one.
Rearming via Windows PowerShell
If you prefer PowerShell, the process is nearly identical. Open Windows PowerShell as Administrator. The slmgr.vbs script is callable from PowerShell as well. Simply run:
cscript c:\windows\system32\slmgr.vbs /rearm
The cscript interpreter is necessary to run the .vbs file. After the command succeeds, restart the server and verify with cscript c:\windows\system32\slmgr.vbs /dlv.
What to Do If the Rearm Command Fails
Sometimes, the /rearm command might not work as expected. Here are the most common issues and their solutions.
Error: “Rearm count exceeded. Additional rearms are not allowed.”
This is the most definitive error. It means you have used all six permitted rearms. At this point, you have three legal options:
– Purchase a full retail license and activate the server with a genuine product key.
– Perform a clean installation of Windows Server 2022 Evaluation on new hardware or a new virtual machine, which starts a fresh 180-day timer with a full set of six rearms.
– If you are using a virtual machine, you can often create a snapshot or checkpoint from before the first activation, revert to it, and start the evaluation fresh. This is common in lab environments.
Error: “Software Licensing Service says the application is running under a remote session.”
This can happen if you are connected via Remote Desktop. The licensing service sometimes blocks rearm operations over remote sessions. The solution is to run the command locally on the server console. If physical access isn’t possible, you might use a baseboard management controller (like iDRAC, iLO, or IPMI) to access a virtual console, or use a PowerShell remote session (Enter-PSSession) which sometimes works where RDP does not.
No Error, But Timer Doesn’t Reset After Reboot
First, double-check your status with slmgr.vbs /dlv. Ensure you are reading the correct expiration field. If it truly didn’t reset, try the rearm process one more time, ensuring you run the command as Administrator and not just a user with admin rights. In rare cases, system file corruption can affect the licensing components. Running a System File Checker scan (sfc /scannow in an admin command prompt) can repair protected system files.
Planning Your Evaluation Period Strategy
Simply knowing how to rearm isn’t enough. You should manage this capability strategically to avoid last-minute crises.
Set a calendar reminder for yourself about 30 days before the evaluation expires. This gives you ample time to either perform the rearm or begin the process of obtaining a permanent license. Do not wait until the final week.
Keep a log. Note down each time you rearm and the new expiration date. A simple text file or spreadsheet can prevent you from losing track and accidentally exceeding the rearm limit.
Understand the end state. When the evaluation period finally expires permanently, Windows Server will begin shutting down every hour. This is not a sustainable state for any environment. Your plan must lead to either a licensed installation or a decommissioned test server.
Is Rearming the Same as Activating?
This is a critical distinction. Rearming only resets the evaluation timer. It does not convert an evaluation installation into a fully licensed one. Activation is the process of permanently licensing the OS using a valid retail, volume, or OEM product key purchased from Microsoft or an authorized distributor. Activation is forever (for that hardware); rearming is a temporary extension.
If you have a product key, you activate the server using the command slmgr.vbs /ipk YOUR-PRODUCT-KEY followed by slmgr.vbs /ato. This will permanently clear the evaluation timer and convert the installation to a standard, licensed edition.
Your Path Forward After Mastering the Rearm
You now hold the key to controlling time on your Windows Server 2022 evaluation. This knowledge removes the pressure of the ticking clock and allows you to focus on what matters: thoroughly testing your workloads, validating configurations, and ensuring your production deployment will be a success.
The next step is to integrate this check into your regular server maintenance routine. During your monthly review of critical systems, include a quick status check on any evaluation servers. Verify their expiration dates and remaining rearm counts. This proactive habit will ensure you’re never caught off guard.
Finally, remember that the evaluation edition is a powerful tool for learning and testing, but it has a boundary. Use the time granted by rearming wisely. Document your findings, finalize your architecture decisions, and prepare for the transition to a fully licensed, supported production environment. Your server is ready to serve, and now you have the time to make sure it does so perfectly.
