Symptoms
In systems that do not have MDAC 2.1 installed on them, when you use the FoxPro ODBC ISAM Driver (named “Microsoft FoxProDriver(*.dbf)” in the ODBC Administrator) for 2.5 or 2.6 tables, it allowsyou to view the contents of a table created in Visual FoxPro. However, whenyou try to update or add new records, the following error message mightappear:

Operation must use an Updateable Query.
Resolution
The older ISAM driver is not able to accurately read the table header ofthe Visual FoxPro table. Visual FoxPro supplies additional information inthe header of the table for links to a database container, which the olderISAM ODBC driver does not accommodate. Snapshot recordsets are updateableas long as the table is in 2.5 or 2.6 format.