C# IIS error 'Microsoft.Ace.OLEDB.12.0' provider is not registered解决

IIS error System.InvalidOperationException: The 'Microsoft.Ace.OLEDB.12.0' provider is not registered on the local machine.
Because of you installed 32bit Microsoft.Ace.OLEDB.12.0 dll 因为你安装了 32bit的dll

1.    Open the IIS 7.5 manager and select the application pool corresponding to your web application.
2.    Right click the application pool and select ‘Advanced settings’.
3.    Select the field ‘Enable 32-bit applications’ and change it to 'true'.
4.    Restart your application pool and access your application to fix the error you saw.