SQL Developer

I am using sqldeveloper on windows 7 . The sql developer version is given below
Java(TM) Platform 1.6.0_23
Oracle IDE 2.1.1.64.45
Versioning Support 2.1.1.64.45

I am getting this error while connecting to the db.
IO exception: The Network Adaptor couldnt establish the connection.
Vendor code: 17002

I am able to connect the db through the command prompt.
---------------------
Listener status
---------------------
C:\Users\Dev D>lsnrctl status

LSNRCTL for 32-bit Windows: Version 10.2.0.1.0 - Production on 19-DEC-2010 12:43:52

Copyright (c) 1991, 2005, Oracle. All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for 32-bit Windows: Version 10.2.0.1.0 - Production
Start Date 19-DEC-2010 12:26:31
Uptime 0 days 0 hr. 17 min. 21 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Default Service XE
Listener Parameter File C:\oraclexe\app\oracle\product\10.2.0\server\network\admin\listener.ora
Listener Log File C:\oraclexe\app\oracle\product\10.2.0\server\network\log\listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC_FOR_XEipc)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=DevD-PC)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=8080))(Presentation=HTTP)(Session=RAW))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "XEXDB" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
Service "XE_XPT" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
Service "xe" has 1 instance(s).
Instance "xe", status READY, has 1 handler(s) for this service...
The command completed successfully

----------
tnsping
----------

C:\Users\Dev D>tnsping xe

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production on 19-DEC-2010 12:49:39

Copyright (c) 1997, 2005, Oracle. All rights reserved.

Used parameter files:
C:\oraclexe\app\oracle\product\10.2.0\server\network\admin\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = DevD-PC)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = XE)))
OK (14000 msec)

*********
tnsnames.ora

***********

XE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = DevD-PC)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = XE)
)
)

EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
)

ORACLR_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
)
(CONNECT_DATA =
(SID = CLRExtProc)
(PRESENTATION = RO)
)
)

*******
listener.ora
*********

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = C:\oraclexe\app\oracle\product\10.2.0\server)
(PROGRAM = extproc)
)
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = C:\oraclexe\app\oracle\product\10.2.0\server)
(PROGRAM = extproc)
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
(ADDRESS = (PROTOCOL = TCP)(HOST = DevD-PC)(PORT = 1521))
)
)

DEFAULT_SERVICE_LISTENER = (XE)


Could someone help me what am i missing here