Visit the official Microsoft Download Center. Search for ".NET Framework 4.8 Offline Installer."
This is a larger, standalone package (roughly 115 MB) that contains all the files needed for installation. microsoft net framework 4.8 32 bit windows 7
.NET Framework 4.8 requires Windows 7 Service Pack 1 (SP1) . If you haven't updated to SP1, the installer will fail. How to Download and Install Visit the official Microsoft Download Center