Windows NT and Windows 2000

On Windows NT and Windows 2000, ODBC.INI and ODBCINST.INI are not text files, but subkeys of the Windows registry. (The Windows registry is a binary database maintained by the operating system. The registry partitions information in it through a hierarchy of keys.)

User data sources are stored under the HKEY_CURRENT_USER key and are available only to the current user. System data sources are stored under the HKEY_LOCAL_MACHINE key and can be used by more than one user.

For user data sources, the complete registry key is HKEY_CURRENT_USER\Software\ODBC\ODBC.INI. Within this level, the format of ODBC.INI is the same as described in the previous section.

The ODBCINST.INI subkey is a subkey of HKEY_LOCAL_MACHINE. Like the text file on Windows, it describes the number and types of ODBC drivers installed on the system. The ODBC Data Source Administrator reads the subkey when it invokes the driver’s setup DLL to add or modify a data source for the driver.