Network adapter could not establish the connection.

But when i was trying to connect the above server from my neighbours system i am getting an error

But problem is not able to connect the server installed in my mahcine from other system.....

Post (that is copy and paste) what you did and what you got with SQL*Plus.

XE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.10.50.50)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = XE)
)
)

C:\Documents and Settings\u18906>ping 10.10.50.50

Pinging 10.10.50.50 with 32 bytes of data:

Reply from 10.10.50.50: bytes=32 time<1ms TTL=128
Reply from 10.10.50.50: bytes=32 time<1ms TTL=128
Reply from 10.10.50.50: bytes=32 time<1ms TTL=128
Reply from 10.10.50.50: bytes=32 time<1ms TTL=128

Ping statistics for 10.10.50.50:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

C:\Documents and Settings\u18906>tnsping XE

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production on 27-JAN-2010 17:55:05

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 = 10.10.50.50)(PORT = 1521)) (
CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = XE)))
TNS-12535: TNS:operation timed out

C:\Documents and Settings\u18906>