windows 8 - When MS offers a UPDATE choice between [x64 System] and [blank] are they talking about OS or CPU bits

When planning to install a UPDATE to repair a conflict the Microsoft knowledge base offers a choice of two types. Notably one intended [for x64-based system] and the other a generic [] this is CPU architecture labeling.

If this talking about 32-bit vs. 64-bit OS labeling which is kind of what one usually expects when loading updates
OR
is this talking about x86 vs. x64 capable CPUs that are often spoken of as systems.

You see I have a 32-bit OS (W8.1pro) on an Intel x64 processor.

The question 32bit OS, x64 based processor in Windows 8.1 does not answer my problems it relates to new software installations. The questions linked there are interesting but not related to MS KB naming conventions

So what update I should apply when Microsoft offers choices labelled by CPU but probably intended to match the OS?

Secondary question, except for the wasted download will there be any serious problem if Windows is offered the wrong bit length upgrade?

Edit

I tried to load both options, both of them said they are Not applicable to your system even though they were the recommended fix.

The page that offered the updates was https://support.microsoft.com/en-us/kb/2938322/en-us and the symptoms are consistent with my situation. I forgot to link it earlier.

Answer

I just noticed now that there was a 3rd option in many of the updates, it included [for Windows Server 2012 R2] with the [for x64-based systems] and generic [] so they MUST be talking about the OS and not the CPU architecture.

So in this case the x64 is referring to 64-bit OS and not CPU architecture.