Microsoft had stated that that 4.8.1 would be available by default on Windows 11 22H2. The tech giant delivered the most updated version of .NET Framework 4.8.1 on 22H2 back in February (KB5022497). You can download it from the Update Catalog website here.
Earlier today, alongside the monthly Patch Tuesdays, Redmond announced that it will begin delivering its .NET Framework version 4.8.1 update on older versions of Windows 11 and Windows 10. This will happen via the Windows Update as well as via Microsoft Update Catalog, starting with the Release Preview Insider channel. On a blog post, the company has explained how it plans to release the framework across Windows 11 21H2, Windows 10 22H2, and more:
.NET Framework 4.8.1 will be available for the following versions of Windows and distribution channels:
- Windows Update: Windows 11 21H2, Windows 10 21H2 (LTSC), and Windows 10 22H2
- Microsoft Update Catalog: Windows 11 21H2, Windows 10 21H2 (LTSC), Windows 10 22H2 and Windows Server 2022 (Desktop, Azure Editions), Azure Stack 21H2 and Azure Stack 22H2.
Note: Customers using Windows Server Updates Services (WSUS) or any other update management tools will be able to import the .NET Framework 4.8.1 product from the Microsoft Update Catalog. Also note that .NET Framework 4.8.1 is already included by default in newer versions of Windows, starting with Windows 11 22H2.
You can find the official blog post here where you can find more details.