CMD ora-12560 Protocol Adapter error

This problem I solved for a long time, in fact, the crux of the problem is that I installed a oracle11g database on this machine and installed an Oracle Client, resulting in an error reporting a protocol adapter when using the Sqlplus/as sysdba link. Because the linked server or client cannot be judged by using Sqlplus/as sysdba link cmd.

Workaround:

1, not casually Baidu said open Oracleoradb11g_home1listener and ORACLESERVICEORCL and set the environment variables Oracle_home=d:\app\lgswork\product\11.2.0\ Dbhome_1 and ORACLE_SID=ORCL.

2, the actual solution: Delete the environment variable in the path of the client section can be

CMD ora-12560 Protocol Adapter error