Hi,

I'm trying to install a PL/SQL Developer 14 on a Windows 7 PC.
I've downloaded and unzipped Oracle Instant Client 18.5, no installation seems to be required, just an unzip.
Under the same directory I've create the network/admin/tnsnames.ora files and set the directory as "Oci Library" on Preferences -> Oracle -> Connection.
I cannot understand how to go on, PL/SQL Developer doesn't seems to detect then tnsnames.ora file.

Thanks in advance

try adding instantclient=C:\<path to instant client folder> to the shortcut to run PL/SQL Developer. So it know where to look at start.

Hi there,
I just have a similar problem with the latest oracle client Version 19.9.0.0.0 (Basic Package) on Windows 10.
oci.dll is placed at "C:\oracle\instantclient" and I added in the pl sql developer the paths:
Oracle home : c:\oracle\instantclient
OCI library : c:\oracle\instantclient\oci.dll

At startup while connectiong to a database I receive the error

"Inizialization error
Could not initialize "c:\oracle\instantclient\oci.dll"
Make sure you have the 64 Bits Oracle Client installed.

Believe me, it's 64 bit … any idea?

Is it necessary in this case to put something in Oracle Home?

To use the Instant Client you need to set the following environment variables:

• PATH
  Needs to include the Instant Client directory (where oci.dll is located).
• TNS_ADMIN
  Needs to point to the directory where tnsnames.ora is located.
• NLS_LANG=language_territory.characterset
  Defines the language, territory, and character set for the client. For example:
  NLS_LANG=AMERICAN_AMERICA.WE8MSWIN1252

Note that the 64 bit 19.9 Oracle Instant Client Basic package requires the Microsoft Visual Studio 2017 Redistributable:

https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads

Thanks Marco Kalter. This solved my Problem. For any other guys looking this topic, I did not set any variable at all.