Today, after installing Oracle Database 11g R2 Client there was no ODBC driver listed under Data Sources (ODBC) window. First I tried to change Setup type to Administrator, then Instant Client, etc… noting worked.
Then I remembered my last issue with Same / different file problem on 64-bit / WoW64. As you remember, you cannot load 32-bit DLL, driver, etc. in 64-bit process. Read more about WoW64.
The problem is, that I have installed 32-bit Oracle on 64-bit Windows.
Now there are two options:
- Install 64-bit Oracle;
- If you can not do 1. (my case), then you can access 32-bit ODBC under:
Start - Run - %windir%\SysWOW64\odbcad32.exe
Microsoft have article The 32-bit version of the ODBC Administrator tool and the 64-bit version of the ODBC Administrator tool display both the 32-bit user DSNs and the 64-bit user DSNs in a 64-bit version of the Windows operating system.