Toad Data Point does not list any database names under Database drop down of Login window.
Oracle client and TNSNames file have been configured.
Search for the tnsnames.ora file, if tnsnames.ora file is being used as a method of connection.
Check that this TNSNAMES.ora file is valid and located in the correct folder.
By default (unless specified using the TNS_ADMIN variable), it should be in your %ORACLE_HOME%\Network\Admin folder.
Open the tnsnames.ora file via Notepad or a text editor application and verify that all entries are correct such as the HOST, SID/SERVICE_NAME, PORT number information.
If TNS_ADMIN has been set under the registry or as an environment variable, then make sure that the TNSNAMES.ORA file is in the directory specified for TNS_ADMIN.
If a TNS_ADMIN environment variable does not exist, add a new entry and enter the correct path.
