Hello Sheila and welcome to the forum.
Can you break it down for us.....
Are you having trouble "opening" (.xls, .xlsx) files in Excel
OR
Are you having trouble printing those files, once they are open in Excel (from within the application.
Additionally some extra information might be helpful
Version of Excel you are using?
Printer you are using?
Error if any you are getting?
What happens during the process?
Any other printing problems in other applications?