Installing 10g client next to 11g database on same computer I have Oracle 11.2.0.1.0 installed on Windows 7 64 bit

I want to import data from warehouse which has Oracle 10.2.0.4.0 installed.

When I try to import 

impdp usr/pass@WAREHOUSE TABLES=TABLE DIRECTORY=DATA_PUMP_DIR NETWORK_LINK=D_W VERSION=10.2


It gives :

UDI-00018: Data Pump client is incompatible with database version 10.2.0.4.0


To overcome version incompatibility, I will install 10g client on my computer.

But I already have 11gr2 database installed, so I wanted to learn about potential problems. 

Especially about having two Oracle Homes, tnsnames.ora files, etc..

Thanks.
You could live quiet safety with two ORACLE_HOMEs if you know:


%TNS_ADMIN% is your tnsnames.ora / listener.ora / sqlnet.ora directory for both;
in your %PATH% you should specify the right order for your preferred oracle bin;
there's a Oracle_home_selector installed somehere (I don't remember) in full client install
take a look at Windows Registry (something like HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE)
pay attention to %NLS_LANG%