Plsql Connect Oracle Hint ORA-12154 solution

Oracle Server: Red Hat Linux 5.10 x64
Oracle version: 10g 10.2.0.5.0 x64
Plsql machine System: Windows Server 2003 SP2 x64
Plsql Machine Database client version: Oracle 10g x32
Plsql version: 9.0.6.1665 x32

Phenomenon:

PLSQL Login Hint Ora-12154:tns: Unable to resolve specified connection identifier
Sqlplus can be connected properly in the cmd command.
The Sqlplus worksheet from the Oracle client is normal.

Solution idea:

View the Tnsnames.ora file, which is configured correctly and lacks parentheses.
Use the Tnsping [instance name] method from the command line to see if you can parse correctly.
Use the Sqlplus command to see if normal, excluding the possibility of Tnsnames.ora.
Plsql "Tools"-"preferences", Connections, Oracle home directory names and OCI libraries are correct, choose your own correct, log back in and try again.

Workaround:

Looked at the bottom of the basic is no problem, but still the error. Then try to copy the Plsql to another directory.

After viewing, the original plsql was installed in C:\Program Files (x86) \plsql Developer Directory

Reason guessing:

64-bit system installation 32-bit programs default to the program Files (x86) directory, including two parentheses can cause problems with the Plsql database.
Move the Plsql Developer directory to the C:\Program files directory and log in again to solve the problem.