An error stating "Cannot find OCI DLL" error may result when connecting to TOAD with an Oracle 10G Instant Client.
WORKAROUND:
1) Go to Start | Run | Regedit to access your local registry
2) Add the following key node: HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE
STATUS:
This issue is fixed in TOAD 8.5.3.2. This version can be downloaded at http://questsupportlink.quest.com
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