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You can use Excel Calculation Services to handle processor-intensive calculations from your Office SharePoint Server 2007 team site and to control access to external data.
This demo shows you the basic steps for enabling Excel Services for a document library, such as adding the document and data connection libraries to the list of trusted file locations, and creating a data connection to a data provider in Excel Services. Watch and learn how you can control access to important internal information and external data connections.
How to do it (text version):
