One of my developer encountered similar issue in this nice article .
His creates Visual Basic form in MS Office Excel to pull data from Oracle database, while the Excel is 32 bits installed in his 64 bits windows 7 , hence requires 32 bits ODBC for this to work.
Launch 32bit ODBC configuration program (ODBC Data Source ) C:\Windows\SysWOW64, we can see there is "Microsoft ODBC for Oracle". This is the same finding for his target depLoying server (windows 2008R2). I was thinking no more 32bits "Microsoft ODBC for Oracle" in windows 2008, which is wrong.
The server has 64 bits oracle client already installed for other application,
Luckily I notice there is 32bit ODBC for 11g instantclient. This is help to minimize the impact.
Follow the instantclient ODBC installation guide :
1. run odbc_install.exe as administrator in command prompt.
2. Append path of instantclient (e:\instantclient11203) to system environment variable PATH
3. create tnsnames.ora in e:\instantclient11203\netwoork\admin\
Missing part of the guide is : Launch 32bit ODBC configuration program (ODBC Data Source ) C:\Windows\SysWOW64\odbcad32.exe,
After this, my developer told me that his program can run suddenly.
Reference:
MS ODBC for Oracle
Oracle ODBC Centre