New Window Server 2025 Instance Only Allows f2 Instance Types

Thank you for your assistance. See attached screen shots. I think this might have something to do with the availability zone. When I switch to Ohio us-east-2 no problems. This is not ideal however as all my other resources are located in us-east-1.

The issue you're experiencing with limited instance type options for Windows Server 2025 is likely due to a misunderstanding of the compatibility requirements for this new operating system version.

Windows Server 2025 AMIs are designed to support Nitro-based instances with Unified Extensible Firmware Interface (UEFI) to provide enhanced security and better performance. These AMIs do not support Xen-based instances, which includes many older instance types.

The T3 instance family you're trying to select is not compatible with the Windows Server 2025 AMI. This is because Windows Server 2025 requires instances that support UEFI boot mode, which T3 instances do not.

The f2 instance types you're seeing as available options are likely Nitro-based instances that support UEFI and are therefore compatible with Windows Server 2025. However, it's unusual that only these specific instance types are available, as Windows Server 2025 should support a wider range of Nitro-based instances.

To resolve this issue, you should:

1. Verify that you're using the correct AMI for Windows Server 2025.
2. Check if there are other Nitro-based instance types available in your region that support UEFI boot mode.
3. If you specifically need to use an instance type that doesn't support UEFI (like T3), you may need to use a different Windows Server version or look for a Windows Server 2025 AMI with the prefix "BIOS-" which is designed for Legacy BIOS-only instances.

If you continue to experience issues or see unexpected limitations in instance type availability, it would be advisable to contact AWS support for further assistance, as there might be region-specific constraints or other factors affecting your options.
Sources
Microsoft FAQ – AWS
Changes in Windows Server AMIs by OS version - AWS Windows AMIs

Hello.

I can successfully select t3 instance types in my AWS account.
Could you please share the AMI ID you are trying to use?
By the way, I have confirmed that "ami-02e3d076cbd5c28fa" in us-east-1 in my AWS account allows me to select t3 instance types.