There are technically two versions of the driver included in the installation, which can confuse newcomers:

Modern workstations and servers almost exclusively run 64-bit operating systems. However, applications vary. If you are running a 64-bit version of Microsoft Office (which is the standard now) or a 64-bit custom application, you use the 64-bit PostgreSQL ODBC driver.

Deploying the 64-bit driver requires downloading the correct installer from the PostgreSQL ODBC download site (or via a package manager like Chocolatey). A critical failure occurs when a user inadvertently installs the 32-bit driver and wonders why their 64-bit application’s ODBC administrator shows no drivers. Troubleshooting also involves checking the PostgreSQL pg_hba.conf file for proper authentication methods (e.g., md5 or scram-sha-256 ) and ensuring firewalls allow traffic on port 5432. Modern versions of the driver support PostgreSQL's robust authentication mechanisms, including Kerberos and GSSAPI, enabling single sign-on in Active Directory environments.

A is essential for connecting modern 64-bit applications—such as Microsoft Excel , Power BI , and Tableau—directly to a PostgreSQL database . 1. Downloading the Right Driver

To make the database accessible to your applications, you must create a Data Source Name (DSN).

The 64-bit version of the Odbcad32.exe file is located in the %systemdrive%\Windows\System32 folder. Microsoft Learn Create an ODBC data source on 64-bit computers

Setting up the driver is a straightforward process, but it requires navigating the Windows ODBC Data Source Administrator correctly.

: Select the -x64.zip file for 64-bit systems. A version containing no platform suffix often includes both 32-bit and 64-bit installers .

Select from the list of drivers and click Finish .

: Always click the Test button to verify the connection before clicking Save . 4. Key Differences: 64-bit vs. 32-bit

If you attempt to use a 32-bit driver with a 64-bit application, the connection will fail or simply not appear in the data source selection menu. Conversely, if you are supporting legacy 32-bit software, you must install the 32-bit driver, even on a 64-bit OS.