Error when using Oracle Instant Client with Toad: "Home is not valid" (4241131)

After installing an Oracle Instant Client, Toad complains that the Oracle home is invalid. Opening the Home Editor indicated the following messages:

"Home is not valid!"
"This Oracle home is invalid"

SQLPlus is working fine.

Disclaimer: Quest does not provide support for problems that arise from improper modification of the registry. The Windows registry contains information critical to your computer and applications. Make sure you back up the registry before modifying it. For more information on the Windows Registry Editor and how to back up and restore it, refer to Microsoft Article ID 256986 "Description of the Microsoft Windows registry": http://support.microsoft.com/default.aspx?kbid=256986.

RESOLUTION:

1. You should have a directory structure similar to the following:
   c:\Program Files\oracle
   c:\Program Files\oracle\bin
   c:\Program Files\oracle\network\admin
2. Uncompress the downloaded Oracle instant client under c:\Program Files\oracle\bin
3. Add the following environment variables in your System Properties (My Computer | Properties | Advanced | Environment Variables | System variables)
   SQL_PATH = c:\Program Files\oracle
   TNS_ADMIN c:\Program Files\oracle\network\admin
4. Place your tnsnames.ora file under c:\Program Files\oracle\network\admin
5. Start | Run | Regedit | Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\
6. Add a new Key called ORACLE
7. Under ORACLE, add a new string value called ORACLE_HOME and enter C:\Program Files\Oracle for the value data
8. Close and Open Toad again

To see video of how to install and configure an Oracle instant client watch SOL76453: How to install and configure an Oracle Instant Client for use with Toad for Oracle?.