After installing Oracle 9i R2 (9.2.0.1.0) and installing PL/SQL Developer, I could get SQL*Plus to work, but not PL/SQL Developer. It kept complaining that it could not find "the OCI DLL"
I noted that Oracles install (in ORAHOME/bin) had ociw32.dll, and NOT oci.dll. After much hacking and...