Determining an Installation Database's Code Page
To determine the code page of a database, call MsiDatabaseExport with hDatabase set to the handle of the database and szTableName set to _ForceCodepage. This exports a text file with an .idt extension. The first two lines of this file are blank. The third line is the ANSI code page number, followed by a tab, followed by the name _ForceCodepage. See also Code Page Handling of Imported and Exported Tables.
An example of determining the code page by using the Export method is provided in the Windows Installer SDK as a part of the utility WiLangId.vbs. For more information about using WiLangId.vbs see the topic: Manage Language and Codepage.