Access 2007 Mail Merge fails to Execute. ODBC error

The path to you ODBC database is configured in your ODBC settings. Where this is updated for Office 2007 depends if you have a 32 or 64 bit OS.

If you have a 32-bit OS use the Database Sources (ODBC) under Administrative Tools

If you have a 64-bit OS use Database sources (ODBC) from c:\windows\SysWOW64\odbcad32.exe

Office 2007 is a 32 bit application and can only read 32-bit ODBC data souces. Using the settings under Administrative tools on a 64-bit machine sets ODBC for 64-bit applications. Confusing I know.

Here's one reference on this http://support.microsoft.com/kb/942976