"[Microsoft]ODBC Driver Manager]Datasource name not found and no default driver

ACTION:
In Excel, you try to refresh the data imported from an external datasource (Oracle database).

RESULT:
You receive the following error message:
"[Microsoft]ODBC Driver Manager]Datasource name not found and no default driver specified"

CAUSE:
The source was imported from an Oracle database, but Oracle client 9.2.0.6 was missing on the user’s computer.

RESOLUTION:
installed Oracle client 9.2.0.6 on the user's computer and the worksheet is now working.