# EC2 Fast Launch prerequisites for Windows
<a name="win-start-fast-launch-prereqs"></a>

Before you set up EC2 Fast Launch, verify that you've met the following prerequisites that are required to create snapshots for the AMIs in your AWS account:
+ If you provide a custom launch template when you configure EC2 Fast Launch, the service uses the VPC and other configuration settings that you've defined in the launch template. For more information, see [Use a launch template when you set up EC2 Fast Launch](win-fast-launch-configure.md#win-fast-launch-with-template).
+ If you don't use a custom launch template to configure your settings, you must attach the [EC2FastLaunchFullAccess](security-iam-awsmanpol.md#security-iam-awsmanpol-EC2FastLaunchFullAccess) policy to your current IAM role before you enable EC2 Fast Launch. Then the service automatically creates an CloudFormation stack with the following resources in your AWS account.
  + A virtual private cloud (VPC)
  + Private subnets across multiple Availability Zones
  + A launch template configured with Instance Metadata Service Version 2 (IMDSv2)
  + A security group with no inbound or outbound rules
+ Private EC2 Fast Launch AMIs must support user data script execution.
+ To configure EC2 Fast Launch for an AMI, you must create the AMI using **Sysprep** with the shutdown option. The EC2 Fast Launch feature doesn't currently support AMIs that were created from a running instance.

  To create an AMI using **Sysprep**, see [Create an Amazon EC2 AMI using Windows Sysprep](ami-create-win-sysprep.md).
+ To enable EC2 Fast Launch for an [encrypted AMI](AMIEncryption.md) that uses a customer managed key for encryption, you must grant the service-linked role for EC2 Fast Launch permission to use the CMK. For more information, see [Access to customer managed keys](slr-windows-fast-launch.md#win-faster-launching-slr-access-to-cust-keys).
+ The default quota for **Max parallel launches** across all AMIs in an AWS account is 40 per Region. You can request a Service Quotas increase for your account, as follows.

  1. Open the Service Quotas console at [https://console.aws.amazon.com/servicequotas/](https://console.aws.amazon.com/servicequotas/).

  1. In the navigation pane, choose AWS services.

  1. In the search bar, enter **EC2 Fast Launch**, and select the result.

  1. Select the link for **Parallel instance launches** to open the service quota detail page.

  1. Choose **Request increase at account level**.

  For more information, see [Requesting a quota increase](https://docs.aws.amazon.com/servicequotas/latest/userguide/request-quota-increase.html) in the *Service Quotas User Guide*.