Recently, I installed the Oracle 12c Runtime client on a handful of Windows 2012 servers. Without thinking much about it, I installed the 32-bit client (required for some developers tools) and the 64-bit client (or server execution). The client software was installed in the following directories: e:\Oracle\product\12.1.0\Client_1 e:\Oracle\product\12.1.0\Client_2 So, which is the 32-bit install and which is the 64-bit install? This proved to be a more interesting challenge than I thought. to execute 'sqlplus.exe -V' did return the version, but provided no additional details as to the bitness. First, the directory structures in both are exactly the same. 1 With some more intense googling, I found my solution. Windows 2012 labels 32-bit executables in the task manager! As such, I was able to start sqlplus.exe from both client installation folders and look in the task manager. As you can see from the image above, client_2 is my 32bit install. For future re