How to install "Microsoft .NET 9.x.x Windows Server Hosting"?

Hi @川野　連也 ,

Thanks for reaching out.

“Microsoft .NET 9.x.x Windows Server Hosting” isn’t a built-in Windows Server feature. What you need to install is the ASP.NET Core Hosting Bundle for .NET 9.

Here’s the recommended approach:

1. Check supported OS First, make sure your server is supported. .NET 9 is supported on Windows Server 2016 and later (Windows Server 2016, 2019, 2022, and 2025). Older or out-of-support Windows Server versions aren’t listed as supported platforms for .NET 9. While installation may still succeed, these scenarios aren’t covered by Microsoft support and behavior isn’t guaranteed.
2. Download the .NET 9 Hosting Bundle Go to the official .NET 9 download page and select the ASP.NET Core Runtime - Hosting Bundle: https://dotnet.microsoft.com/en-us/download/dotnet/9.0. This bundle installs:
   • .NET 9 Runtime
   • ASP.NET Core Runtime
   • ASP.NET Core Module (ANCM) required for IIS
3. Run the installer as Administrator Execute the dotnet-hosting-9.x.x-win.exe installer on your Windows Server and complete the setup.
4. Ensure IIS is installed Confirm that the Web Server (IIS) role is installed. If IIS was added after the hosting bundle, rerun or repair the hosting bundle so the ASP.NET Core Module is correctly registered. IIS hosting guidance: https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/?view=aspnetcore-10.0
5. Restart IIS After installation, restart IIS to make sure the ASP.NET Core Module is fully loaded:

      iisreset
   

6. Verify installation Run the following command to confirm the runtimes are installed:

      dotnet --list-runtimes
   

   You should see .NET 9.0 and Microsoft.AspNetCore.App 9.0 listed.

For more details, the official Hosting Bundle documentation is here:

https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/hosting-bundle?view=aspnetcore-10.0

Hope this helps! If my answer was helpful - kindly follow the instructions here so others with the same problem can benefit as well.