If you cannot locate the original 4.5 offline installer, consider using or 4.8 , as they are backward compatible with most apps requiring 4.5. For strict compatibility, offline installers for 4.5 are still mirrored on trusted tech archives (always verify SHA-1 hashes).
The safest download location is Microsoft’s official download center. However, note that Microsoft has since superseded .NET 4.5 with 4.5.1, 4.5.2, 4.6, 4.7, and 4.8. Direct links to the original .NET 4.5 offline installer may redirect to newer versions. net framework 4.5 offline installer for windows 7 32 bit