可以在此处下载

http://www.oracle.com/technology/global/cn/software/tech/oci/instantclient/index.html

将其解压到c:/OracleInstantClient
1.SET PATH=c:/OracleInstantClient
2.SET TNS_ADMIN=c:/OracleInstantClient
3.新建一个tnsnames.ora，然后填入
for example:
192.168.0.123 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.123)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = orcl)
    )
)
4.SET LD_LIBRARY_PATH=c:/OracleInstantClient

5.如果要安装SQL plus那么需要设置SET SQLPATH=c:/OracleInstantClient
6.如果查询结果为乱码，设置set NLS_LANG=XXXX（我自己是SIMPLIFIED CHINESE_CHINA.ZHS16CGB231280）

7.用PL/SQL Developer看是否能连上Oracle就可以判断安装是否成功了