An old recipe that was laying around for Oracle Instant Client 10.2.
Prerequisites
Some good things to know;
1. Oracle Client 10.2 contains some defects that requires the user that is running it to have Create global object permissions.
2. The user needs read-access minimum to the directory you will install the application to. 
Sequence
Installation
Unpack all Oracle-clients to (instantclient-basic-win32-10.2.0.4.zip and instantclient-odbc-win32-10.2.0.4.zip);
C:\instantclient_10_2
Append C:\instantclient_10_2 to the PATH variable
Create tnsnames.ora in c:\instantclient_10_2 with the following content;
# tnsnames.ora Network Configuration File: D:\oracle\product\10.2.0\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.
SERVER.FQDN =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (COMMUNITY = tcp.WORLD)(PROTOCOL = TCP)(HOST = FQDN)(PORT = 1531))
)
(CONNECT_DATA = (SID = name))
)
Execute the following command;
C:\instantclient_10_2>odbc_install.exe JA
Oracle ODBC Driver is installed successfully.
C:\instantclient_10_2>
Configuration
Create a new System DSN
Choose Oracle_in_instantclient10_2