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.
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?.