As the final iteration, 4.8.1 supports modern versions of Windows but has dropped support for some older operating systems that 4.8 still supported: Download .NET Framework - free official downloads
For users needing the most up-to-date, secure, and compatible version of the classic framework, the Official .NET Framework 4.8.1 Offline Installer is the correct choice. What is the .NET Framework 4.8.1 Offline Installer? net+framework+49+offline+installer+for+windows+exclusive
An offline installer (or standalone redistributable) contains all the necessary components to install the framework without requiring an active internet connection during the process. As the final iteration, 4