I am relatively new to ArcMap. I am trying to use an XL spreadsheet in ArcMap. When I try to input this into ArcMap, a message always comes up "Failed to connect to database. An underlying database error has occurred. Class not registered." I have input XL spreadsheets before and have been successful, but now I am not sure why it is not starting up in ArcMap?
Have you reviewed the Understanding how to use Microsoft Excel files in ArcGIS section of the Help, particularly the "few things to keep in mind" items?
Is this an XLS or XLSX file? What version of MS Office do you have installed?