# Upgrade an EC2 Windows instance to a newer version of Windows Server
<a name="serverupgrade"></a>

If it's time to upgrade the Windows Server operating system on your EC2 Windows instance from an earlier version, you can use one of the following methods.

**In-place upgrade**  
An in-place upgrade operates on an existing instance. Only the operating system files are affected during this process, while your settings, server roles, and data are left intact.

**Migration (also known as a side-by-side upgrade)**  
A migration involves capturing settings, configurations, and data, and porting these to a newer operating system on a fresh EC2 Windows instance. You can launch your instance from a public or private Windows AMI that you subscribe to from the AWS Marketplace, or an AMI that's shared with you. You can also create a custom AMI with EC2 Image Builder. See the [Image Builder User Guide](https://docs.aws.amazon.com/imagebuilder/latest/userguide/what-is-image-builder.html) for more information.  
AWS provides a set of publicly available Amazon Machine Images (AMIs) for Windows Server versions that run on EC2 instances. These AMIs are updated on a monthly basis. For information about the latest Windows AMIs, see the [AWS Windows AMI Reference](https://docs.aws.amazon.com/ec2/latest/windows-ami-reference/windows-amis.html).

Microsoft has traditionally recommended migrating to a newer version of Windows Server instead of upgrading in place. Migrating can result in fewer upgrade errors or issues, but can take longer than an in-place upgrade because of the need to provision a new instance, plan for and port applications, and adjust configuration settings on the new instance. An in-place upgrade can be faster, but software incompatibilities can produce errors.

**Topics**
+ [Perform an in-place upgrade on your EC2 Windows instance](os-inplaceupgrade.md)
+ [Use Automation runbooks to upgrade an EC2 Windows instance](automated-upgrades.md)
+ [Migrate an EC2 Windows instance to a Nitro-based instance type](migrating-latest-types.md)
+ [Troubleshoot an operating system upgrade on an EC2 Windows instance](os-upgrade-trbl.md)