Link Oracle 10g (XE) To Sql Server Express

I have been trying to link/connect Oracle XE 10g to Sql Server 2008 Express using Oracle heterogeneous services without any luck. I have MS ODBC drivers loaded on my PC which I know work as I can create and test the connectivity of a DSN which is successful, however when I try to link Oracle to that ODBC driver I get the following error message.

TNS-12545: Connect failed because target host or object does not exist.

Here is listener.ora file.

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
[code]........

# DEFAULT_SERVICE_LISTENER = (XE)

Here is how the tnsnames entry is defined.

SqlServer =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = MYPC-LT)(PORT = 1521))
)
(CONNECT_DATA =
(SID=SqlServer)
)
(HS=OK)
)

Here is a copy of the initSqlServer.ora file.

# This is a sample agent init file that contains the HS parameters that are
# needed for an ODBC Agent.
#
# HS init parameters
[code]......

Just to be clear the ODBC DSN is named "SqlServer". I followed through all of the steps outlined in the following URL.

[URL].......

There seems to be a disconnect between the ODBC driver and SQL*Net. Possibly due to Oracle HS?