Use the 32-bit version of the DLL (which is the only version of dao350.dll that exists).

Navigate to: C:\Program Files (x86)\Common Files\Microsoft Shared\DAO Check if dao350.dll is already there.

Simply dropping a random DLL into a folder rarely fixes the underlying registry issues.

If the file exists on your drive but the program won't run, you need to register it using the Command Prompt. Click the button and type cmd . Right-click cmd.exe and select Run as Administrator .

Search the official Microsoft Download Center for .

If the file is present but the error persists, the file is likely "unregistered," meaning Windows doesn't know it's there. Method 2: Register the DLL Manually

Run the installer. This will place a verified, clean copy of the DLL into the correct system folders and handle the registry entries for you. Method 4: Reinstall the Problematic Application

Since dao350.dll is part of the Jet database components, reinstalling or repairing the Microsoft Jet 3.5 engine can restore the file.