Getting ORA-12154 error connecting to database after installing Toad on Windows 64-bit OS with Oracle Client 10g 32-bit. (4237909)

Any of the following errors can occur when attempting to connect to an Oracle database when installed on a Windows 64-bit OS:

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

"ORA-06413: Connection not opened"

"Can't initialize OCI. Error -1"

This could be caused by an Oracle 10g client defect on Windows 64-bit. Oracle 11g is not affected. According to Oracle Metalink, Doc ID 334528, there is a network issue for any application that is installed into a path with a parenthesis using the 10g client on Windows 64-bit.

For example, C:\Program Files(x86)\Quest Software\

RESOLUTION 1:

If you are running Oracle 10g please install your Quest application into 'C:\Quest Software' and not 'C:\Program Files (x86)\Quest Software.'

Note: If you are trying to install Toad into 'C:\Program Files\Quest Software', Windows will detect it as a 32-bit Program and install it back to 'C:\Program Files (x86)\Quest Software'

RESOLUTION 2:

If you want to keep your install into C:\Program Files (x86)\ Quest Software, then upgrade your client to Oracle 11g 32-bit as the issue is resolved there.

Note: Toad 10.1 to Toad 11.0.1 does support Windows 64-bit but the Oracle client still must be 32-bit.

RESOLUTION 3:

If you are not running Oracle 10g client or if you did not install into C:\Program File (x86) and you are still facing this issue, please check the following:

- Ensure that your Windows User has Administrator Rights before installing an Oracle Client (or Toad).
- During the Oracle Client installation, choose “Full” or “Administrator” installation type (this is not automatically selected).
- Refer to the following solution for general troubleshooting: https://support.quest.com/kb/64853 

This is an issue with all versions of Toad for Oracle.