Upgrade your Oracle Client to a newer version i.e. 11g R2 Client.
Here are the Oracle download pages for Oracle Client Software we recommend and mostly used by Toad users:
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32-bit Oracle 11g R2 Client:
Oracle Database 11g Release 2 Client (11.2.0.1.0) for Microsoft Windows (32-bit)
win32_11gR2_client.zip (684,581,290 bytes)
http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-win32soft-098987.html
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64-bit Oracle 11g R2 Client:
Oracle Database 11g Release 2 Client (11.2.0.1.0) for Microsoft Windows (x64)
win64_11gR2_client.zip (615,698,264 bytes) (cksum - 2947608743)
http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-win64soft-094461.html
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>>>>>>> IMPORTANT NOTES: <<<<<<<<
- During the Oracle Client installation, choose “ADMINISTRATOR” installation type (this is not automatically selected).
- Ensure the “bit” of Toad and Oracle Client matches i.e. both 32-bit or both 64-bit or else it would not work.
- Download ‘directly’ to your “DESKTOP” location (and run it from there too). This can avoid potential download and installation problems.
- Un-Zip the downloaded file. Do not run the Oracle Setup from within the ZIP program or Zipped folder.
- Ensure your Windows User has Administrator Rights before installing an Oracle Client (or Toad).
- Toad for Oracle 11.5.1 and lower supports 32-bit Oracle Clients only. Do NOT use 64-bit Oracle Client.
- The above 32-bit clients will work on 64-bit Windows OS’s.
- Ensure you copy over your TNSNAMES.ORA file (this file usually comes from your company). The default location for this file in 11g is:
11g - C:\app\<YOUR_USER>\product\11.2.0\client_1\NETWORK\ADMIN\
NOTE: After installing the new client, ensure you select it in Toad’s login screen | under “Connect Using:” (ensure you are NOT connected to any database for this setting to be available).