This is the highest and final version of the .NET Framework that supports Windows 7. If you want maximum compatibility with modern apps, this is the one to install. System Requirements for 64-bit Users
Cause: You accidentally downloaded .NET 5/6/8 or .NET 4.8.1. Fix: Re-download .NET Framework 4.8 (not 4.8.1, not "Desktop Runtime").
The most common requirement for software on Windows 7 is .