Error: "ORA - 12154 Could not resolve service name" when tuning SQL followed by an Access Violati (4235005)

Error received before launching SQL Tuning module when trying to tune a SQL Statement from SQL Editor:

"ORA - 12154 Could not resolve service name".

SQL Tuning never comes up. Other work in Toad may bring up Access Violations until task manager is used to close Toad. The connection to the database seems to be find with everything else.

Problem with path in the registry under Oracle.

Check the system registry (Start | Run | "regedit") to verify that the Oracle_Home paths under HKEY_LOCAL_MACHINE | SOFTWARE | ORACLE are pointing to the correct Oracle_Home.

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