Windows 2025 + EC2 Launch Agent V2 breaking userdata behavior

Hello, I'm posting this with the hope that it can save other people the time it took me to figure out.

Solution:

Microsoft has deprecated wmic with Windows Server 2025, which breaks the EC2 launch agent. The issue can be fixed by reinstalling wmic using this command in PowerShell (Admin):

DISM /Online /Add-Capability /CapabilityName:WMIC~~~~

Story time:

Instance type used: g4dn.4xlarge

I've recently started migrating one of our services to Win 2025 ( ami-09cb80360d5069de4 - base Amazon image of Windows 2025 used).

Old setup:

Previously, with version 1 of the "EC2 Launch Agent" we would call "InitializeInstance.ps1" in our scripts to prepare our server for imaging. After an Image was made, we would replace the old ami in the Auto Scaling Group's launch template and terminate the old warm pool instances. This would then trigger a recreation of the warm pool using the new AMI. Our launch templates have a powershell User Data script that runs once during warm-up. Later on, when we needed to scale, the instances were ready to go and would scale relatively fast.

What changed:

With version 2 of the "EC2 Launch Agent" and Windows Server 2025 the "InitializeInstance.ps1" script no longer exists. We replaced the call with EC2Launch.exe sysprep, everything else stayed the same, but here is where the fun began for me.

It turns out that Microsoft removed WMI command-line utility or C:\Windows\System32\wbem\wmic.exe. This causes the launch agent to fail during an initial warm-up of an instance on the step preReady-installEgpuManager-0, marking the stage preReady as failed and skipping the execution of user data. The instance then counts as warmed up and ready to go. However, on scale up, when we expect them to start right up, they have to first go through the user data script.

There is an error being logged in the agent.log file, thanks to which I was able to find the issue: Error: Error running task: failed to run task 'preReady-installEgpuManager-0': fork/exec C:\Windows\System32\wbem\wmic.exe: The system cannot find the file specified.

Please log when the User Data step is skipped. Currently it only logs this:

2025-05-16 12:28:08 Info: Stage: preReady completed.
2025-05-16 12:28:08 Info: User data was not provided. Skip running user data.
2025-05-16 12:28:09 Info: Initialize user-data state.
2025-05-16 12:28:09 Info: User-data state initialized successfully.
2025-05-16 12:28:09 Info: Stage: postReadyUserData completed.

Hopefully, the EC2 team can fix the issue as it is next to silent.