Error: "ORA-12154: TNS: could not resolve service name" with Registry TNS_ADMIN settings. (9053)

The following registry key HKLM\TNS_ADMIN set with C:\TNSADMIN. The only copy of tnsnames.ora on the computer is in this directory.

The SQL Navigator connection interface is able to read the TNSNAMES.ORA file in this location; all the tnsnames.ora entries appear in the drop down list. However SQL Navigator fails with:

"ORA-12154: TNS: could not resolve service name"

****WARNING: Using Registry Editor incorrectly can cause serious problems that can damage the operating system and the software installed. Quest cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.****

Follow the steps below to alter your Oracle registry settings.

1. Select Start | Run, type regedit and press Enter key to start your registry editor.

2. If you have multiple homes in your Oracle installation, determine which Oracle Home SQL Navigator is using to connect, say Homex

3. Go to HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\Homex, right click on Homex and select New | String Value.

4. Rename "New string value #1" as TNS_ADMIN and press Enter.

5. Right click on the string value (TNS_ADMIN) you have just created and select Modify.

6. In the Edit String box, type the path to your tnsnames.ora file. For example, type C:\TNS if location of file is C:\TNS\tnsnames.ora and click OK

****WARNING: Using Registry Editor incorrectly can cause serious problems that can damage the operating system and the software installed. Quest cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.***