If you meant you need a specific file, piece of code, or a fix related to .NET 4.0, please provide more details (e.g., error message, app name, or what you're trying to accomplish).
– it is backward-compatible with applications built for 4.0, 4.5, 4.6, and 4.7. On Windows 10/11, you can enable it via:
It sounds like you're looking for information or a download link for .
This was the grandfather of the async/await pattern we use today.