I know that "processor architecture" can be used to refer to whether the processor is 32-bit or 64-bit (or something else), but what word can be used for the operating system? Note that it's not necessarily the same as the processor architecture, e.g. I can install a 32-bit OS on a 64-bit machine.
Also, this is for a business document for non-technical people, so I'd like to avoid an overly technical terminology.