MDAC 2.5 SDK - ODBC Programmer's Reference
Chapter 19: Configuring Data Sources
The installer DLL maintains information in the registry about each data source. In Microsoft® Windows NT®/Windows 2000 and Microsoft Windows® 95/98, this information is stored in subkeys under one of the following two keys in the registry:
HKEY_LOCAL_MACHINE
SOFTWARE
ODBC
Odbc.ini
HKEY_CURRENT_USER
SOFTWARE
ODBC
Odbc.ini
Which key is used depends on whether the data source is a system data source, which is available to all users, or a user data source, which is available only to the current user. System data sources are stored on the HKEY_LOCAL_MACHINE tree, and user data sources are stored on the HKEY_CURRENT_USER tree. In all other respects, system data sources and user data sources are identical. For information on the registry, see the Win32® SDK documentation.