The most straightforward way to obtain the Excel 120 Object Library DLL is directly from Microsoft:
It allows other programs (like Access or Visual Studio) to "talk" to Excel to create spreadsheets or automate tasks. microsoft excel 120 object library dll free download repack
If you are developing a standalone application (like a C# or VB.NET program) and need to manipulate Excel files without paying for heavy licenses or forcing users to have specific Office versions: The most straightforward way to obtain the Excel