Toad for Oracle Login Screen: TNS Tab Shows Empty Database Name Drop-Down (tnsnames.ora Not Detected) (4302696)

Create the TNS_ADMIN Environment Variable

Follow the steps below to force Toad for Oracle to look for the tnsnames.ora file in a specific location:

1. Open System Properties

   • Right‑click My Computer (or This PC) on the desktop.
   • Select Properties.

2. Access Advanced settings

   • Click Advanced system settings.
   • Select the Advanced tab.

3. Open Environment Variables

   • Click the Environment Variables button.

4. Create the TNS_ADMIN system variable

   • Under System Variables, click New.
   • Enter the following values:
     • Variable name: TNS_ADMIN
     • Variable value: Path to the directory containing the tnsnames.ora file
       (Example: C:\oracle\product\10.2.0\client_1\NETWORK\ADMIN\)
   • Click OK to save.

5. Restart Toad for Oracle

   • Launch Toad for Oracle and re-test the issue to confirm the TNS entries are now populated.