Follow these instructions which have been known to work with Toad for Oracle:
To download an Instant Client, go to the following link:
Select the “instantclient-basic-nt-188.8.131.52.0.zip” file to download.
NOTE: If you wish for the SQL Plus tool for the Instant client, then you can also download the “instantclient-sqlplus-nt-184.108.40.206.0.zip” file.
A. Extract all Instant Client files to one directory file length path.
NOTE: If you downloaded the SQL Plus tool, extract all the files to the same location as the Instant client files. i.e. C:\Ora12c_32bit.
B. Place the new Oracle_Home path of Instant Client to the Environment Variable PATH.
Right click on My Computer and select Properties.
In the Advanced tab select “Environment Variables” button.
In the System Variables section, highlight Path and press edit. Edit your path so that your Oracle Instant Client directory path is first.
For example: PATH=C:\Ora12c_32bit;
NOTE: Ensure you have a semicolon at the end, no space.
- Click OK on all windows.
C. If planning to use TNSnames.ora file to Connect try the following:
Right click on the Computer icon on your Desktop and choose Properties option.
In the System window click on Advanced system settings link in the left pane.
In the System Properties window select Advanced tab and click on Environment Variables button.
Under the System variables section of the new window, NEW button.
Enter TNS_ADMIN for the variable name and for the variable value type in C:\TNSnames.
Then manually create a folder called TNSnames in your (C:) drive and paste your TNSnames.ora file there