Use the EC2Launch v2 agent to perform tasks during EC2 Windows instance launch - Amazon Elastic Compute Cloud
EC2Launch v2 conceptsEC2Launch v2 task overviewEC2Launch v2 directory structureTelemetry

Use the EC2Launch v2 agent to perform tasks during EC2 Windows instance launch

All supported instances of Amazon EC2 that are launched from AWS Windows Server 2022 and Windows Server 2025 AMIs include the EC2Launch v2 launch agent (EC2Launch.exe) by default. We also provide Windows Server 2016 and 2019 AMIs with EC2Launch v2 installed as the default launch agent. These AMIs are provided in addition to the Windows Server 2016 and 2019 AMIs that include EC2Launch v1. You can search for Windows AMIs that include EC2Launch v2 by default by entering the following prefix in your search from the AMIs page in the Amazon EC2 console: EC2LaunchV2-Windows_Server-*.

To compare launch agent version features, see Compare Amazon EC2 launch agents.

EC2Launch v2 performs tasks during instance startup and runs if an instance is stopped and later started, or restarted. EC2Launch v2 can also perform tasks on demand. Some of these tasks are automatically enabled, while others must be enabled manually. The EC2Launch v2 service supports all EC2Config and EC2Launch features.

This service uses a configuration file to control its operation. You can update the configuration file using either a graphical tool or by directly editing it as a single .yml file (agent-config.yml). The service binaries are located in the %ProgramFiles%\Amazon\EC2Launch directory.

EC2Launch v2 publishes Windows event logs to help you troubleshoot errors and set triggers. For more information, see Windows event logs.

The EC2Launch v2 agent supports the following Windows Server operating system (OS) versions:

Supported OS versions

  • Windows Server 2025

  • Windows Server 2022

  • Windows Server 2019 (Long-Term Servicing Channel and Semi-Annual Channel)

  • Windows Server 2016

EC2Launch v2 concepts

The following concepts are useful to understand when considering EC2Launch v2.

Task

You can invoke a task to perform an action on an instance. You can configure tasks in the agent-config.yml file or through user data. For a list of available tasks for EC2Launch v2, see EC2Launch v2 tasks. For task configuration schema and details, see EC2Launch v2 task configuration.

Stage

A stage is a logical grouping of tasks that the EC2Launch v2 agent runs. Some tasks can run only in a specific stage. Others can run in multiple stages. When using agent-config.yml, you must specify a list of stages, and a list of tasks to run within each stage.

The service runs stages in the following order:

Stage 1: Boot

Stage 2: Network

Stage 3: PreReady

Windows is ready

After the PreReady stage completes, the service sends the Windows is ready message to the Amazon EC2 console.

Stage 4: PostReady

User data runs during the PostReady stage. Some script versions run before the agent-config.yml file PostReady stage, and some run after, as follows:

Before agent-config.yml

  • YAML user data version 1.1

  • XML user data

After agent-config.yml

  • YAML user data version 1.0 (legacy version for backwards compatibility)

For example stages and tasks, see Example: agent-config.yml.

When you use user data, you must specify a list of tasks for the launch agent to run. The stage is implied. For example tasks, see Example: user data.

EC2Launch v2 runs the list of tasks in the order that you specify in agent-config.yml and in user data. Stages run sequentially. The next stage starts after the previous stage completes. Tasks also run sequentially.

Frequency

Task frequency determines when tasks should run, depending on the boot context. Most tasks have only one allowed frequency. You can specify a frequency for executeScript tasks.

You will see the following frequencies in the EC2Launch v2 task configuration.

  • Once – The task runs once, when the AMI has booted for the first time (finished Sysprep).

  • Always – The task runs every time that the launch agent runs. The launch agent runs when:

    • an instance starts or restarts

    • the EC2Launch service runs

    • EC2Launch.exe run is invoked

agent-config

agent-config is a file that is located in the configuration folder for EC2Launch v2. It includes configuration for the boot, network, PreReady, and PostReady stages. This file is used to specify the instance configuration for tasks that should run when the AMI is either booted for the first time or for subsequent times.

By default, the EC2Launch v2 installation installs an agent-config file that includes recommended configurations that are used in standard Amazon Windows AMIs. You can update the configuration file to alter the default boot experience for your AMI that EC2Launch v2 specifies.

User data

User data is data that is configurable when you launch an instance. You can update user data to dynamically change how custom AMIs or quickstart AMIs are configured. EC2Launch v2 supports 60 kB user data input length. User data includes only the UserData stage, and therefore runs after the agent-config file. You can enter user data when you launch an instance using the launch instance wizard, or you can modify user data from the EC2 console. For more information about working with user data, see How Amazon EC2 handles user data for Windows instances.

EC2Launch v2 task overview

EC2Launch v2 can perform the following tasks at each boot:

  • Set up new and optionally customized wallpaper that renders information about the instance.

  • Set the attributes for the administrator account that is created on the local machine.

  • Add DNS suffixes to the list of search suffixes. Only suffixes that do not already exist are added to the list.

  • Set drive letters for any additional volumes and extend them to use available space.

  • Write files from the configuration to the disk.

  • Run scripts specified in the EC2Launch v2 config file or from user-data. Scripts from user-data can be plain text or zipped and provided as a base64 format.

  • Run a program with given arguments.

  • Set the computer name.

  • Send instance information to the Amazon EC2 console.

  • Send the RDP certificate thumbprint to the Amazon EC2 console.

  • Dynamically extend the operating system partition to include any unpartitioned space.

  • Run user data. For more information about specifying user data, see EC2Launch v2 task configuration.

  • Set non-persistent static routes to reach the metadata service and AWS KMS servers.

  • Set non-boot partitions to mbr or gpt.

  • Start the Systems Manager service following Sysprep.

  • Optimize ENA settings.

  • Enable OpenSSH for later Windows versions.

  • Enable Jumbo Frames.

  • Set Sysprep to run with EC2Launch v2.

  • Publish Windows event logs.

EC2Launch v2 directory structure

EC2Launch v2 should be installed in the following directories:

  • Service binaries: %ProgramFiles%\Amazon\EC2Launch

  • Service data (settings, log files, and state files): %ProgramData%\Amazon\EC2Launch

Note

By default, Windows hides files and folders under C:\ProgramData. To view EC2Launch v2 directories and files, you must either enter the path in Windows Explorer or change the folder properties to show hidden files and folders.

The %ProgramFiles%\Amazon\EC2Launch directory contains binaries and supporting libraries. It includes the following subdirectories:

  • settings

    • EC2LaunchSettingsUI.exe — user interface for modifying the agent-config.yml file

    • YamlDotNet.dll — DLL for supporting some operations in the user interface

  • tools

    • ebsnvme-id.exe — tool for examining the metadata of the EBS volumes on the instance

    • AWSAcpiSpcrReader.exe — tool for determining the correct COM port to use

    • EC2LaunchEventMessage.dll — DLL for supporting the Windows event logging for EC2Launch.

  • service

    • EC2LaunchService.exe — Windows service executable that is launched when the launch agent runs as a service.

  • EC2Launch.exe — main EC2Launch executable

  • EC2LaunchAgentAttribution.txt — attribution for code used within EC2 Launch

The %ProgramData%\Amazon\EC2Launch directory contains the following subdirectories. All of the data produced by the service, including logs, configuration, and state, is stored in this directory.

  • config – Configuration

    The service configuration file is stored in this directory as agent-config.yml. This file can be updated to modify, add, or remove default tasks run by the service. Permission to create files in this directory is restricted to the administrator account to prevent privilege escalation.

  • log – Instance logs

    Logs for the service (agent.log), console (console.log), performance (bench.log), errors (err.log), and telemetry (telemetry.log are stored in this directory. Log files are appended to on subsequent executions of the service.

  • state – Service state data

    The state that the service uses to determine which tasks should run is stored here. There is a .run-once file that indicates whether the service has already run after Sysprep (so tasks with a frequency of once will be skipped on the next run). This subdirectory includes a state.json and previous-state.json to track the status of each task.

  • sysprep – Sysprep

    This directory contains files that are used to determine which operations to perform by Sysprep when it creates a customized Windows AMI that can be reused.

  • wallpaper – Wallpaper

    This wallpaper images is stored in this directory.

Telemetry

Telemetry is additional information that helps AWS to better understand your requirements, diagnose issues, and deliver features to improve your experience with AWS services.

EC2Launch v2 version 2.0.592 and later collect telemetry, such as usage metrics and errors. This data is collected from the Amazon EC2 instance on which EC2Launch v2 runs. This includes all Windows AMIs owned by AWS.

The following types of telemetry are collected by EC2Launch v2:

  • Usage information — agent commands, install method, and scheduled run frequency.

  • Errors and diagnostic information — agent installation error codes, run error codes, and error call stacks.

Examples of collected data:

2021/07/15 21:44:12Z: EC2LaunchTelemetry: IsAgentScheduledPerBoot=true
2021/07/15 21:44:12Z: EC2LaunchTelemetry: IsUserDataScheduledPerBoot=true
2021/07/15 21:44:12Z: EC2LaunchTelemetry: AgentCommandCode=1
2021/07/15 21:44:12Z: EC2LaunchTelemetry: AgentCommandErrorCode=5
2021/07/15 21:44:12Z: EC2LaunchTelemetry: AgentInstallCode=2
2021/07/15 21:44:12Z: EC2LaunchTelemetry: AgentInstallErrorCode=0

Telemetry is enabled by default. You can disable telemetry collection at any time. If telemetry is enabled, EC2Launch v2 sends telemetry data without additional customer notifications.

Telemetry visibility

When telemetry is enabled, it appears in the Amazon EC2 console output as follows.

2021/07/15 21:44:12Z: Telemetry: <Data>
Disable telemetry on an instance

To disable telemetry for a single instance, you can either set a system environment variable, or use the MSI to modify the installation.

To disable telemetry by setting a system environment variable, run the following command as an administrator.

setx /M EC2LAUNCH_TELEMETRY 0

To disable telemetry using the MSI, run the following command after you download the MSI. 

msiexec /i ".\AmazonEC2Launch.msi" Remove="Telemetry" /q
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