ORA-12560: TNS Protocol Adapter Error(ORACLE 11g)

Question

i installed 11g on my laptop yesterday and it was working perfectly but today it keeps writing:(AS SHOWN BELOW)
========================================================================
SQL*Plus: Release 11.2.0.1.0 Production on Fri May 20 12:26:48 2011
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Enter user-name: hr
Enter password:
ERROR:
ORA-12560: TNS:protocol adapter error
Enter user-name: hr
Enter password:
ERROR:
ORA-12560: TNS:protocol adapter error
Enter user-name:
===============================================================================
I checked the listener status and it seems to be working quite well as shown below...i don't understand!
================================================================================
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Users\Bryan>lsnrctl status
LSNRCTL for 32-bit Windows: Version 11.2.0.1.0 - Production on 20-MAY-2011 12:31
:07
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1522)))
STATUS of the LISTENER
Alias LISTENER
Version TNSLSNR for 32-bit Windows: Version 11.2.0.1.0 - Produ
ction
Start Date 20-MAY-2011 09:30:43
Uptime 0 days 3 hr. 0 min. 24 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File C:\app\Bryan\product\11.2.0\dbhome_2\network\admin\lis
tener.ora
Listener Log File c:\app\bryan\diag\tnslsnr\Bryan-PC\listener\alert\log.
xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC1522ipc)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1522)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
===========================================================================
i dont know wat happened PLEASE ASSIST

Answer 1

Hello,
I am having the same problem, my step son touched the computer and have no idea what he did.
here are my results
lsnrctl services
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Users\Rami>lsnrctl services
LSNRCTL for 32-bit Windows: Version 11.2.0.2.0 - Production on 17-JAN-2013 23:22
:23
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0
LOCAL SERVER
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0
LOCAL SERVER
The command completed successfully
C:\Users\Rami>