Unable to connect to Siebel Server using Tools

I got this error……………..

I did everything as per the requisites as per this post,
1.) Make TNS entry for required server in TNSNAMES.ORA
2.) Create an ODBC entry for that TNS
3.) Make all required changes in CFG file

I googled this error and got following suggestions…
1.) Check your TNS entry may be its not correct
2.) Check your ODBC connections
3.) Your ORACLE_HOME and PATH may not set properly
4.) Check your CFG changes, it should contain Connection String, Gateway Name & Enterprise Name

But I have reinstalled Oracle twice as ODBC Test Connection connected successfully. So, it seems that it unable to find TNSNAMES.ORA file.

Finally, I checked my tools log file and came to know about  tns error – ORA-12154: TNS:could not resolve the connect identifier specifiedIt simply says that what connect String given in  CFG file is not correct. I got the answer…

My fault:
I have mentioned ODBC name in Connect String in CFG. 

Solution:
Connect String in CFG should be TNS name from TNSNAMES.ORA file.

Here I am giving snapshot of DATASERVERSRC section from CFG with all required params highlighted in RED.

[ServerDataSrc]

Docked                   = TRUE

ConnectString            = SIEBEL        (This should be TNS name)

TableOwner               = SIEBEL

DLL                      = sscdo90.dll

SqlStyle                 = OracleCBO

MaxCachedCursors         = 16

MaxCachedDataSets        = 16

ReverseFillThreshold     = 100

CaseInsensitive          = FALSE

InsensitivityFactor      = 2

FileSystem               = E:/FS

GatewayAddress           = localhost     (Mention your Gateway Name)

EnterpriseServer         = localhost        (Mention your Enterprise Name)

CurrentSQLID             = CHANGE_ME

MaxCursorSize            = -1

PrefetchSize             = -1

Hope this will help someone as it helps me. Please correct me, if I am wrong somewhere.

@AskmeSiebel