right now downloaded the instant client from http://www.oracle.com/technetwork/topics/winx64soft-089540.html
and I see this at the end of this page:
1. Download the appropriate Instant Client packages for your platform. All installations REQUIRE the Basic package.
2. Unzip the packages into a single directory such as "instantclient".
3. Set the library loading path in your environment to the directory in Step 2 ("instantclient"). On many UNIX platforms, LD_LIBRARY_PATH is the appropriate environment variable. On Windows, PATH should be used.
4. Start your application and enjoy.
however, PATH has been set and oracle client application like Toad for Oracle still can't find client, how come and how to solve this?