I was working recently on an import script that would allow the end user upload an excel file, read it and import the data. Everything worked great on my own computer but when I ran the project on our Windows Server 2003 the project would fail when attempting to open the .xlsx file. The error returned to me was:
Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine
Obviously the server was missing the component required to read in a xlsx excel file. To solve this issue you need to download the 2007 Office System Driver: Data Connectivity Components onto your server. No server restart is required to install this tool and once it is installed everything will work as expected and your .net project will be allowed open and read .xlsx files.