Do not use .NET 5.0 in production due to security vulnerabilities. Upgrade to .NET 8.0 (Long Term Support).
First and foremost,
If a newer version of .NET is already installed, the installer may block the process. In some cases, you must enable the feature via "Turn Windows features on or off" in the Control Panel. net framework 5.2 offline installer
Unlike modern "web installers" that download files on the fly, the (also called the "standalone package") allows you to install the software on a machine with no internet connection. Do not use