For Qlabel 1.19/1.38 or Golabel Label Design Applications - 

If unable to connect to Excel , and the error comes as Provider is not installed. 

Please download " Microsoft Access Database Engine 2010 Redistributable "

https://www.microsoft.com/en-us/download/details.aspx?id=13255

"Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine error"