To use this with Orable (my dodgy Oracle Query IDE) I need to download the Oracle Instant Client (32 bit) from here:
http://www.oracle.com/technetwork/topics/winsoft-085727.html
You need to provide login credentials to Oracle, so they've got that now, darn them.
Download it, unzip it to somewhere that all users on your machine can access it.
Then add it's location to your PATH.
e.g. I just added this to my path
;C:\wip\Oracle\instantclient-basic-nt-12.1.0.2.0\instantclient_12_1
I think needed to restart Orable (infact I had to restart the instance of visual studio that launched Orable)