I am having difficulty getting Instant Client to establish an ODBC link to Excel 2007, a 32-bit app. My OS is Windows 7 Professional x64 on a Windows 2008 domain.
I installed Oracle 11g Client 64-bit (11.2.0.3.0), Instant Client Basic 64bit, and Instant Client ODBC 64bit. Path and TNSNAMES parameters were set correctly, and I was able to use Windows Admin Tools to successfully establish a connection to PowerSchool's Oracle database. So far, so good.
When I tried to use this connection in Excel 2007, I got an error message stating that "the specified DSN contains an architecture mismatch between the Driver and Application." More research led me to conclude that I need to install 32-bit Instant Client Basic and ODBC.
So I downloaded the appropriate versions of both of these, installed it into c:\ora\<username>\product\11.2.0\client32 (a sibling to the 64-bit client_2 folder), and now I'm stumped. Running windows\sysWOW64\odbcad2.exe, I see what I think is the 64-bit client, which gives an error message about incompatible architecture (again, 64 vs 32 bit).
What parameters need to be set with odbcad2.exe, and how? Do I need to run the odbcconf.exe program in sysWOW64? I tried adding the ...\client32 folder to PATH; no effect. Is this described in excruciating detail anywhere?