When trying to connect to a database using Toad for Oracle on a Windows 7 64-bit or Windows Server 2003 2008 64-bit operating system, the following error occurs:
Can't initialize OCI. Error -1
The Oracle client installed is a 32-bit Oracle client.
RESOLUTION 1:
Right-click the Toad for Oracle shortcut and select "Run as Administrator" to avoid the error.
RESOLUTION 2:
Right-click the Toad for Oracle shortcut | Properties | Compatibility Tab | check mark "Run this program in compatibility mode for" | choose "Windows XP Service Pack 3" from the drop-down list.
RESOLUTION 3:
Right-click My Computer | Properties | Advanced tab | Environment Variables | under ‘System Variables’ (lower part) | check if you have an entry for ORACLE_HOME. If yes, rename it to ORACLE_HOME_OLD, and then re-test the issue.
RESOLUTION 4:
Upgrade your Oracle client to a version that is 10.2.0.4 or later, preferably 11g.
RESOLUTION 5:
Uninstall your Toad and re-install in 'C:\Quest Software\' instead of the default folder location.
RESOLUTION 6:
Turn off User Account Control (UAC) in Windows.
For other common Oracle connection problems in Toad for Oracle 10.5 and above, please review SOL64853
