I know this issue is going to sound very similar to other issues reported in the past, but I'm running out of ideas. Here are the particulars of my system:

• Windows Server 2012 R2 Standard (64-bit)

• PostgreSQL version() string (from the BigSQL installer PostgreSQL-9.6.1-1-win64-bigsql.exe) :
  version | PostgreSQL 9.6.1 on x86_64-pc-mingw64, compiled by gcc.exe (Rev5, Built by MSYS2 project) 4.9.2, 64-bit

• PostgreSQL installed at F:\PostgreSQL\pg96

• Oracle Client 12.2.0.1 64bit (not the Instant Client, although I tried that first), installed at F:\oracle\product\12.2.0.2 (yes, the last digit of the directory does not match the patch level)

• oracle_fdw 1.5.0 from download file "oracle_fdw-1.5.0-pg96-win64.zip"

• WIndows System PATH: F:\oracle\product\12.2.0.2\bin;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0;F:\PostgreSQL\pg96\bin

• Windows System ORACLE_HOME=F:\oracle\product\12.2.0.2

I copied the oracle_fdw.dll file to F:\PostgreSQL\pg96\lib\postgresql, where other extension DLLs appear to live, and copied the *.sql and oracle_fdw.control to F:\PostgreSQL\pg96\share\postgresql\extension, where other extension SQL and CONTROL files appear to live.

The extension is visible from the "pg_available_extensions" view.

After configuring the environment, I logged out and back in (but did not reboot the server). Then I restarted the Postgres service so it would pick up the PATH changes.

The Postgres service is running as the "Local System" account. The necessary directories and files are all readable/writable to SYSTEM.

When I try to create the extension from PSQL, I get the following error:

dbname=# CREATE EXTENSION oracle_fdw;
ERROR: could not load library "F:/PostgreSQL/pg96/../pg96/lib/postgresql/oracle_fdw.dll": The specified module could not be found.

I've read other postings about this error and ensured my PATH was correct. Could the fact that PostgreSQL is 9.6.1 instead of 9.6.0 be causing the problem? I did not compile my Postgres from source since I don't have a development environment.

Thank you for your help!