Oracle ORA-12557: TNS:protocol adapter not loadable
Oracle Error ORA-12557 – TNS:protocol adapter not loadable occurs on my Windows machine whenever I want to access sqlplus using command prompt.
Once hit [Enter] button after issuing command sqlplus / as sysdba, an unwanted popup appear and it said:
The procedure entry point snlseFreeSecAttrib could not be located in the dynamic link library oranl10.dll
I don’t really know how come this error come hehe, but it must be related to Windows Environment or Oracle Home PATH because sqlplus command works smoothly when I execute it inside ORACLE_HOME\bin.
Okay, let we see what’s wrong with the Windows Environment.
RUN: SYSDM.CPL to open Windows System Properties
Click on Advanced Tab > Environment Variables…
Click the Path variable under System Variable, then click Edit…
This is the original Path
Let we change the order between Oracle Client Home and Oracle DB Home:
From: D:\oracle\product\10.2.0\client_1\bin;D:\oracle\product\10.2.0\db_1\bin;
To: D:\oracle\product\10.2.0\db_1\bin;D:\oracle\product\10.2.0\client_1\bin;
in other words, put the Oracle DB Home in front of the other path.
Click OK to save the changes.
Open new command prompt and write down sqlplus / as sysdba
Eh, it work.. 
Hmm…let me try this tomorrow
i have the same issue with NBU on my Oracle server. thanks!
it worked for my! yees!
windows 2008 r2
Oracle Database 11g Release 2 11.2.0.1.0 (x64)
ODAC 11.2 Release 3 (11.2.0.2.1) with Oracle Developer Tools for Visual Studio
That is the Rocking solution for making oracle 11g 32bit and 64bit clients working on the windows 7. Appreciate your help…!!!
Hi Himanshu, glad to know that
Thanks for your help… issue is resolved now.!!!
Glad to know that Anupam & Mayur
Many Thanks for help…………….
Good one, thanks !!!
hey man thanks a lot
Thank you friend..It helped me resolve the error!..
Thanks a lot…it worked for me too.
This is very helpful.
Thanks.
txs man u helped me alot………
Thanks man, that saved me a lot of pain & time.