Win32vs64OdbcAdmin Using ODBC (32-bit and 64-bit) on 64-bit Windows Using ODBC (32-bit and 64-bit) on 64-bit Windows 64-bit Windows has some surprising and counterintuitive setup and behavior around 32-bit and 64-bit ODBC. Many 64-bit environments still support 32-bit applications, and these require 32-bit ODBC drivers and DSNs, so it's important to understand how this all works.Both the 32-bit and 64-bit ODBC Administrator are named odbcad32.exe. They are differentiated by their filesystem location.The 32-bit ODBC Administrator is found at %systemdrive%/Windows/SysWoW64/odbcad32.exe. This controls 32-bit ODBC drivers, which are required by 32-bit client applications. (The 32-bit ODBC Administrator cannot be accessed through the Control Panels interface; the Data Sources (ODBC) control panel is the 64-bit ODBC Administrator.)Counterintuitively, the 64-bit ODBC Administrator is found at %systemdrive%/Windows/System32/odbcad32.exe. This controls 64-bit ODBC drivers, which are required by 64-bit client applications. (The 64-bit ODBC Administrator can also be accessed through the Control Panels interface, as the Data Sources (ODBC) control panel.) Typical Paths to ODBC Administrators <tgroup><thead /><tbody> <row><entry> </entry><entry> <emphasis>64-bit Windows</emphasis> </entry><entry> <emphasis>32-bit Windows</emphasis> </entry></row> <row><entry> <emphasis>64-bit Administrator</emphasis> </entry><entry> <emphasis><span style="color: red"> UNKNOWN tag: http://www.w3.org/1999/xhtml:nowikiC:\Windows\System32\odbcad32.exe</span></emphasis> or <emphasis>Start</emphasis> -> <emphasis>Control Panels</emphasis> -> <emphasis>Data Sources (ODBC)</emphasis> </entry><entry> n/a </entry></row> <row><entry> <emphasis>32-bit Administrator</emphasis> </entry><entry> <emphasis><span style="color: red"> UNKNOWN tag: http://www.w3.org/1999/xhtml:nowikiC:\Windows\SysWoW64\odbcad32.exe</span></emphasis> <emphasis>not a control panel</emphasis> </entry><entry> <emphasis><span style="color: red"> UNKNOWN tag: http://www.w3.org/1999/xhtml:nowikiC:\Windows\System32\odbcad32.exe</span></emphasis> or <emphasis>Start</emphasis> -> <emphasis>Control Panels</emphasis> -> <emphasis>Data Sources (ODBC)</emphasis> </entry></row> </tbody></tgroup></table> <para> Note that the 32-bit Administrator, and all 32-bit ODBC applications (typically installed to <emphasis>%systemdrive%/Program Files (x86)/</emphasis>), will list 64-bit User DSNs (that is, DSNs based on 64-bit ODBC drivers) -- <emphasis>even though these DSNs and drivers cannot be used by the 32-bit tools/applications.</emphasis></para><para>Likewise, the 64-bit Administrator, and all 64-bit ODBC applications (typically installed to <emphasis>%systemdrive%/Program Files/</emphasis>), will list 32-bit User DSNs (that is, DSNs based on 32-bit ODBC drivers) -- <emphasis>even though these DSNs and drivers cannot be used by the 64-bit tools/applications.</emphasis></para><para>System DSNs will only be seen by the applications and tools which can use them -- 32-bit DSNs for 32-bit applications, and 64-bit DSNs for 64-bit applications. For this reason among others, we strongly advise using only System DSNs in 64-bit environments.</para><para>It can be tempting -- and in some ways useful -- to use identical names for 32-bit and 64-bit DSNs. This is fine -- but you then need to be <emphasis>very</emphasis> careful to keep the 32-bit and 64-bit DSN configurations in sync, as different output resulting from different configurations can lead to undesired and unexpected results in the end, especially in scenarios where tools invisibly mix 32-bit and 64-bit components (as some versions of Microsoft SQL Server and Visual Studio are known to do).</para><bridgehead class="http://www.w3.org/1999/xhtml:h2"> Related </bridgehead> <itemizedlist mark="bullet" spacing="compact"><listitem> <ulink url="MsSqlOn64bitWin">Special Considerations when using Visual Studio and/or Microsoft SQL Server as the Data Consumer, on 64-bit Windows</ulink> </listitem> </itemizedlist></section></docbook>