Amazon Elastic Compute Cloud
User Guide for Windows Instances

Best Practices for Windows on Amazon EC2

This list of practices will help you get the best results from running Windows on Amazon EC2.

Update Windows Drivers

Maintain the latest drivers on all Windows EC2 instances to ensure the latest issue fixes and performance enhancements are applied across your fleet. Depending on your instance type, you should update AWS PV, ENA, and NVMe drivers.

Launch New Instances with the Latest Windows AMIs

AWS releases new Windows AMIs each month, which contain the latest OS patches, drivers, and launch agents. You should leverage the latest AMI when you launch new instances or when you build your own custom images.

Test System/Application Performance Before Migration

Migrating enterprise applications to AWS can involve many variables and configurations. Always performance test the EC2 solution to ensure that:

  • Instance types are properly configured, including instance size, enhanced networking, and tenancy (shared or dedicated).

  • Instance topology is appropriate for the workload and leverages high-performance features when necessary (dedicated tenancy, placement groups, instance store volumes, bare metal).

Update Launch Agents

Update to the latest EC2Config (2012 R2 and earlier) or EC2Launch (2016 and later) agents to ensure the latest issue fixes are applied across your fleet.

Security and Network

  • Manage access to AWS resources and APIs using identity federation, IAM users, and IAM roles. Establish credential management policies and procedures for creating, distributing, rotating, and revoking AWS access credentials. For more information, see IAM Best Practices in the IAM User Guide.

  • Implement the least permissive rules for your security group. For more information, see Security Group Rules.

  • Regularly patch, update, and secure the operating system and applications on your instance. For more information about updating Amazon Linux 2 or the Amazon Linux AMI, see Managing Software on Your Linux Instance in the Amazon EC2 User Guide for Linux Instances. For more information about updating your Windows instance, see Updating Your Windows Instance.


  • Use separate Amazon EBS volumes for the operating system versus your data. Ensure that the volume with your data persists after instance termination. For more information, see Preserving Amazon EBS Volumes on Instance Termination.

  • Use the instance store available for your instance to store temporary data. Remember that the data stored in instance store is deleted when you stop or terminate your instance. If you use instance store for database storage, ensure that you have a cluster with a replication factor that ensures fault tolerance.

Resource Management

Backup and Recovery

  • Regularly back up your EBS volumes using Amazon EBS snapshots, and create an Amazon Machine Image (AMI) from your instance to save the configuration as a template for launching future instances.

  • Deploy critical components of your application across multiple Availability Zones, and replicate your data appropriately.

  • Design your applications to handle dynamic IP addressing when your instance restarts. For more information, see Amazon EC2 Instance IP Addressing.

  • Monitor and respond to events. For more information, see Monitoring Amazon EC2.

  • Ensure that you are prepared to handle failover. For a basic solution, you can manually attach a network interface or Elastic IP address to a replacement instance. For more information, see Elastic Network Interfaces. For an automated solution, you can use Amazon EC2 Auto Scaling. For more information, see the Amazon EC2 Auto Scaling User Guide.

  • Regularly test the process of recovering your instances and Amazon EBS volumes if they fail.