If you are trying to import data from Microsoft Excel (2007-2010) into SQL Server and getting this error,
The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine. (System.Data)
it means Microsoft Access Database Engine OLE DB Provider 12.0 component is missing on your machine.
Microsoft's site no longer offers the install file for that component but you can find it at Internet Archive (Wayback Machine).
Download, install, reboot and it should resolve the issue.