The most common version of this pack found on modern systems. It is cumulative , meaning it includes all the files from the 4.0.1 and 4.0.2 packs, so you only need to install 4.0.3 to target those earlier versions. Why Developers Use It

Build apps for users who may not have upgraded to the latest .NET version .

The .NET Framework 4 Multi-Targeting Pack is typically distributed in two ways:

Without this pack, when you try to build a project targeting .NET Framework 4, your build tools might fall back to the latest installed version (say, .NET 4.8), potentially allowing APIs that don't exist in .NET 4—leading to nasty runtime crashes.