SCOTT/TIGER@DBSERVER
ORA-12170: TNS:CONNECT TIMEOUT OCCURED

dbserver =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.3)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = ORCL)
    )
  )

Try to:
1/ ping the server
2/ tnsping the service

Regards
Michel

ping 192.168.1.3

tnsping dbserver

C:\Documents and Settings\Administrator>ping 192.168.1.3

Pinging 192.168.1.3 with 32 bytes of data:

Request timed out.
Request timed out.

C:\Documents and Settings\Administrator>tnsping dbserver

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production on 27-JUN-2
010 12:16:39

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

Used parameter files:
C:\oracle\product\10.2.0\db_1\network\admin\sqlnet.ora

TNS-03505: Failed to resolve name

ORA-12541: TNS:no Listner

C:\Documents and Settings\Administrator>lsnrctl start listner

LSNRCTL for 32-bit Windows: Version 10.2.0.1.0 - Production on 28-JUN-2010 00:30
:36

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

Starting tnslsnr: please wait...


TNSLSNR for 32-bit Windows: Version 10.2.0.1.0 - Production
System parameter file is C:\oracle\product\10.2.0\db_1\network\admin\listener.or
a
Log messages written to C:\oracle\product\10.2.0\db_1\network\log\listner.log
TNS-01151: Missing listener name, listner, in LISTENER.ORA


Listener failed to start. See the error message(s) above...

# listener.ora Network Configuration File: C:\oracle\product\10.2.0\db_1\network\admin\listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = C:\oracle\product\10.2.0\db_1)
      (PROGRAM = extproc)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = kirmani)(PORT = 1521))
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = kirmani)(PORT = 1521))
    )
  )