How To: Fix The ‘Microsoft.Jet.OLEDB.4.0’ provider is not registered on the local machine.

This error is fairly simple to fix. There is no 64-bit Microsoft.Jet.OLEDB.4.0 provider, so you simply need to set the Application Pool for the site in question to 32-bit and the error should go away.

To do this:

1. Open the Internet Information Services (IIS) Manager GUI
2. Click on Application Pools on the left-hand side
3. Then click on the application pool for the site in question
4. Click on Advanced Settings on the right hand side under Actions > Edit Application Pool
5. Toggle Enable 32-Bit Applications from False to True, and click OK.

Before:

After:

The error should be gone 🥳