Error: 'You have no oracle clients installed'

Hi everyone,

I’ve a problem after install Toad for Oracle version 9.0 to my company server (which run on oracle10g as the server) Once open Toad program, then I get the error message ‘You have no oracle clients installed’. Once I click OK then program is opened properly. I’ve tried to create the connection using TNSNAME but again get the same message. Anyone can help me to fix this out. Thanks in advance for your help.

error message.jpeg