The installer DLL maintains information in the registry about each data source. On Windows NT and Windows 95, 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.