The first step: Download the instant client package on the ORALCE official website to load the Oracle instantclient Basic packages. The address is as follows: Http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html,Instant Client for Microsoft Windows (32-bit) Select the appropriate version to download. Step Two: Unpack the package 1> unzip the compressed file to a local path, such as C:\Oracle\instantclient_11_2. 2> Create folder Network/admin under this path, create Tnsnames.ora file under ADMIN folder, file content is TNS information of database that want to connect. For example:        ORCL = ( DESCRIPTION = (address_list = (ADDRESS = (PROTOCOL = TCP) (HOST = 127.0.0.1) (PORT = 1521) ) ) (Connect_data = (service_name = ORCL) ) ) Step Three: Configure the environment variable Nls_lang:americanoracle_home:c:\oracle\instantclient_11_2path:c:\ Oracle\instantclient_11_2; tns_admin:c:\oracle\instantclient_11_2\network\admin Fourth Step: Configure PL/SQL developer start PL/SQL developer, In the Login window interface, click the Cancel button to make the main interface, click Tools->preferences, in the connection need to configure the following two parameters: oracle home:c:\oracle\instantclient_11_2 oci Library:c:\oracle\instantclient_11_2\oci.dll This configuration is complete, now can be normal use of PL/SQL developer if you want to delete this client, delete environment variables and files.
PL/SQL startup hint missing MSVCR71.DLL: under D:\oracle\product\10.2.0\db_1\BIN\ctxhx
Copy it to the 32-bit client.
64-bit machine's PL/SQL does not install 32-bit Oracle connection mode
