Oracle Database Discussions

Hello ,

I have installed Oracle 11.2.0 64 bit database on my Windows 7 ( Home Premium) PC which is also 64 bit. I installed it because I am trying to setup Informatica. Later, I learnt that informatica is 32 bit and can not communicate to Oracle 11.2.0 64 bit database. So after digging through solutions, someone mentioned that I need to install Oracle 11g client 32bit.
I have installed 11g client software successfully now. Here is problem though :

When I launch SQL-Plus from 11g database , it works fine. However I launch SQL-Plus from 32bit client it gives me error as :
Ora-12560 :TNS: Protocol Adapter Error.

So I have been trying to resolve this error. I saw that this question has been posted many many times and have tried many thing as listed below :
1. copy tnsnames.ora from database ( dbhome_1) to client installation ( client_1 ) under ..\network\admin\ --- Didn't work.
2. Set $ORACLE_HOME and $ORACLE_SID environment variable.
Here is interesting fact - If I set $ORACLE_HOME to database path and not client path error changes to :
ORA-12557 TNS: Protocol adapter not loadable.
If I keep $ORACLE_HOME as client path then I get same error as earlier ORA-12560.
3. I have also tried changing $PATH variable. I did set to path containing only database installation, only client installation, both database and client installation with database installation appearing first

But all of these haven't worked.

Can anyone please suggest what I am missing and any further things I could try ?

Thank you in advance !