ORA-12154 When Connecting Using an Oracle 10G Instant Client (11936)

The following error may result when connecting to SQL Navigator with an Oracle 10G Instant Client:

"ORA-12154: TNS:could not resolve the connect identifier."

RESOLUTION:

The TNS_ADMIN path will need to be added to the environment variables and/or the local registry. To do so, try the following:

Environment Variables:
1) Right click on the My Computer icon on the desktop and select Properties
2) Select the Advanced Tab
3) Click Environment Variables
4) Under the 'System Variables' window select New
5) Enter TNS_ADMIN for the 'Variable name' and the path to your tnsnames.ora file in the 'Variable value' boxes.
--For example if your tnsnames.ora resides in folder c:\oraclient10g\network\admin then this is the path you would specify as the 'Variable value.'
6) Click Ok for changes to take effect
7) Reboot your pc

Local Registry:
1) Go to Start | Run | Regedit
2) Go to HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE
3) On the right hand pane, right-click and select New | String Value
4) Right-click on new entry and rename the file to "TNS_ADMIN"
5) Double-click on "TNS_ADMIN" and enter the path of your tnsnames.ora file
--ie: D:\ORACLE\ORA81\Network\Admin
6) F5 or View | Refresh to save the entry