Microsoft Access Database Engine

-- Connecting to an Excel file, you can query specific sheets SELECT * FROM [Sheet1$] INNER JOIN [Sheet2$] ON [Sheet1$].ID = [Sheet2$].ID;

Your application is running in a different bitness (e.g., 64-bit) than the installed driver (e.g., 32-bit). Fix:

The Microsoft Access Database Engine is a mature, battle-tested data access layer that has quietly powered countless integrations for over two decades. While it shows its age—particularly in the bitness installation nightmare and its Windows-only nature—it remains the most reliable way to programmatically interact with Access databases and Office files using standard SQL.

You are trying to open a newer Access file ( .accdb ) with the old Jet driver ( Microsoft.Jet.OLEDB.4.0 ), or the file is corrupt. Fix: Switch your provider to Microsoft.ACE.OLEDB.12.0 .