Snlinaddrlocalhost Error while connecting to 10gR2 Database on Windows XP

I encountered this strange error on one of my testing database when i tried to connect to the database using sqlplus.exe (command line) and not through sqlplusw.exe.

Error Message Popup “Procedure Entry Point Snlinaddrlocalhost Could Not Be Located In The Oranl10.Dll”

Environment Details

10gR2 DB Oracle Home : C:\oracle\product\1020
10gAS Oracle Home: C:\product\as\1020

To troubleshoot this further i opened windows explorer and launched sqlplus.exe from the ORACLE_HOME/bin. (sqlplus version -> 10.2.0.1) This time i didnt get the error.

I verified all the necessary environemnt variables (under User Variables for the logged in user) viz., ORACLE_SID, ORACLE_HOME, PATH, TNS_ADMIN, but still i encountered this error when i tried to connect to db using command line sqlplus.exe.
(Start -> Run -> sqlplus)

But this time i noticed that the command line is launching the sqlplus.exe from 10gAS Oracle Home and not from 10gR2 Oracle Home. This is kinda strange since my PATH variable has 10gR2 Oracle Home/bin as the first entry.

My actual settings for user variables

ORACLE_HOME = C:\oracle\product\1020\
ORACLE_SID = INST
PATH = C:\oracle\product\1020\BIN;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;C:\oracle\product\as\1020\bin;C:\oracle\product\as\1020\jlib;
TNS_ADMIN = c:\oracle\product\1020\network\admin

Even though my user variables are set properly, the PATH variable value under System Variables has the 10gAS Oracle Home/bin as the first entry. That is the culprit. So i changed the PATH variable to have 10gR2 Oracle Home as the first entry.

I launched sqlplus.exe again from command prompt and this time it picked up the correct oracle home (10gR2 Oracle Home) and the not so popular error “Procedure Entry Point Snlinaddrlocalhost Could Not Be Located In The Oranl10.Dll” vanished.

cheers,
OraclePitStop