Oracle Database Discussions

Hi, my name is Gregory,
I am a newbie in oracle forum here, and need some help from the database guru here...
I am trying to create the database link from Oracle database to SQL Server.
here are the information:
host name of OracleDB = a3500
host name/Ip of SQL Server = 172.16.1.58
SQL Server database name = CKS_VSSD
i had create the new initntchsql.ora file under tg4msql\admin folder, and i also had create the new listener.
here is the file contains

############ initntchsql.ora ###################
HS_FDS_CONNECT_INFO="SERVER=172.16.1.58;DATABASE=CKS_VSSD"
HS_FDS_TRACE_LEVEL=OFF
HS_FDS_RECOVERY_ACCOUNT=RECOVER
HS_FDS_RECOVERY_PWD=RECOVER

############ listener.ora ######################
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = a3500)(PORT = 1521))
)
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
)
(ADDRESS LIST=
(ADDRESS = (PROTOCOL = TCP)(HOST = a3500)(PORT = 1521))
)
)
)

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = C:\oracle\ora92)
(PROGRAM = extproc)
)
(SID_DESC =
(GLOBAL_DBNAME = orclems)
(ORACLE_HOME = C:\oracle\ora92)
(SID_NAME = orclems)
)
(SID_DESC =
(GLOBAL_DBNAME = cps4)
(ORACLE_HOME = C:\oracle\ora92)
(SID_NAME = cps4)
)
(SID_DESC =
(PROGRAM = tg4msql)
(SID_NAME = NTCHSQL)
(ORACLE_HOME = C:\Oracle\Ora92)
)

)

#################### tnsnames.ora #################
...
...
...

NTCHSQL =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = a3500)(PORT = 1521))
)
(CONNECT_DATA =
(SID = NTCHSQL)
)
(HS = OK)
)

and i had created databaselink named ntchsql
then i select statement:
select * from vssd50@ntchsql

and error occured:
ORA-02068: Following severe error from NTCHSQL
ORA-28511: lost RPC connection to heterogenous remote agent using SID=%s
ORA-28509: unable to establish a connection to non-Oracle system


did i missed something on the configuration?
oya... i also see other thread that said i have to comment
SQLNET.AUTHENTICATION_SERVICES = (NTS)
from sqlnet.ora file, and i did that, and the error still the same...

can somebody help me?