ORA-12560 and ORA-12504

Question

I recently installed Oracle XE 11g
Windows 7 PRO x64
this are the installation data:
Destination Folder: C:\oraclexe\
Oracle Home: C:\oraclexe\app\oracle\product\11.2.0\server\
Oracle Base:C:\oraclexe\
Port for 'Oracle Database Listener': 1521
Port for 'Oracle Services for Microsoft Transaction Server': 2030
Port for 'Oracle HTTP Listener': 8080
When I tried to connect
SQL*Plus: Release 11.2.0.2.0 Production on Fri Sep 5 14:57:39 2014
Copyright (c) 1982, 2010, Oracle.  All rights reserved.
SQL> connect
Enter user-name: system
Enter password:
ERROR:
ORA-12560: TNS:protocol adapter error
SQL> connect
Enter user-name: system@jmontoyaz
Enter password:
ERROR:
ORA-12504: TNS:listener was not given the SERVICE_NAME in CONNECT_DATA
SQL>
Any clue?

Answer 1

C:\Users\jmontoyaz>sqlplus / as sysdba
SQL*Plus: Release 11.2.0.2.0 Production on Fri Sep 5 17:07:05 2014
Copyright (c) 1982, 2010, Oracle.  All rights reserved.
ERROR:
ORA-12560: TNS:protocol adapter error
Enter user-name:
ERROR:
ORA-12560: TNS:protocol adapter error
Enter user-name:
ERROR:
ORA-12560: TNS:protocol adapter error
SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus
C:\Users\jmontoyaz>sqlplus / as sysdba startup
SQL*Plus: Release 11.2.0.2.0 Production
Copyright (c) 1982, 2010, Oracle.  All rights reserved.
Use SQL*Plus to execute SQL, PL/SQL and SQL*Plus statements.
Usage 1: sqlplus -H | -V
    -H             Displays the SQL*Plus version and the
                   usage help.
    -V             Displays the SQL*Plus version.
Usage 2: sqlplus [ [<option>] [{logon | /nolog}] [<start>] ]
  <option> is: [-C <version>] [-L] [-M "<options>"] [-R <level>] [-S]
    -C <version>   Sets the compatibility of affected commands to the
                   version specified by <version>.  The version has
                   the form "x.y[.z]".  For example, -C 10.2.0
    -L             Attempts to log on just once, instead of
                   reprompting on error.
    -M "<options>" Sets automatic HTML markup of output.  The options
                   have the form:
                   HTML [ON|OFF] [HEAD text] [BODY text] [TABLE text]
                   [ENTMAP {ON|OFF}] [SPOOL {ON|OFF}] [PRE[FORMAT] {ON|OFF}]
    -R <level>     Sets restricted mode to disable SQL*Plus commands
                   that interact with the file system.  The level can
                   be 1, 2 or 3.  The most restrictive is -R 3 which
                   disables all user commands interacting with the
                   file system.
    -S             Sets silent mode which suppresses the display of
                   the SQL*Plus banner, prompts, and echoing of
                   commands.
  <logon> is: {<username>[/<password>][@<connect_identifier>] | / }
              [AS {SYSDBA | SYSOPER | SYSASM}] [EDITION=value]
    Specifies the database account username, password and connect
    identifier for the database connection.  Without a connect
    identifier, SQL*Plus connects to the default database.
    The AS SYSDBA, AS SYSOPER and AS SYSASM  options are database
    administration privileges.
    <connect_identifier> can be in the form of Net Service Name
    or Easy Connect.
      @[<net_service_name> | [//]Host[:Port]/<service_name>]
        <net_service_name> is a simple name for a service that resolves
        to a connect descriptor.
        Example: Connect to database using Net Service Name and the
                 database net service name is ORCL.
           sqlplus myusername/mypassword@ORCL
        Host specifies the host name or IP address of the database
        server computer.
        Port specifies the listening port on the database server.
        <service_name> specifies the service name of the database you
        want to access.
        Example: Connect to database using Easy Connect and the
                 Service name is ORCL.
           sqlplus myusername/mypassword@Host/ORCL
    The /NOLOG option starts SQL*Plus without connecting to a
    database.
    The EDITION specifies the value for Session Edition.
  <start> is: @<URL>|<filename>[.<ext>] [<parameter> ...]
    Runs the specified SQL*Plus script from a web server (URL) or the
    local file system (filename.ext) with specified parameters that
    will be assigned to substitution variables in the script.
When SQL*Plus starts, and after CONNECT commands, the site profile
(e.g. $ORACLE_HOME/sqlplus/admin/glogin.sql) and the user profile
(e.g. login.sql in the working directory) are run.  The files may
contain SQL*Plus commands.
Refer to the SQL*Plus User's Guide and Reference for more information.
C:\Users\jmontoyaz>