Assuming you have the dbase ODBC drivers installed you can setup a system DSN that points to you dbase file(s). Then configure the linked server to use the Microsoft OLE DB Provider for ODBC. See the BOL article "OLE DB Provider for ODBC" for more information.
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If most people are not willing to see the difficulty, this is mainly because, consciously or unconsciously, they assume that it will be they who will settle these questions for the others, and because they are convinced of their own capacity to do this. -Friedrich August von Hayek
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