Installing Oracle 32bit and 64bit client on the same machine
Solution 1:
I've used this persons guide to installing both versions for .NET developers for a few years now, works like a charm.
How to install 32 and 64 bit versions of Oracle Client
-Stephen
Solution 2:
In my scenario, I need both clients because I have ESRI's ArcMap application (32 bit) and also their Server product (64 bit) on the same machine. I installed the 64 bit client with no problems a couple days ago and just got around to installing the Desktop application. Now I need the 32 bit Oracle client. The installer was failing stating it couldn't "access the temporary location." I am an admin on the box and that is not the problem. The problem was simply that the OracleRemExecServiceV2 service was running on the machine. I stopped the service and the 32 bit client installation proceeded.