Previously it was found that H87 and B85 motherboards could be modified to support 4670K CPU's and overclock them as a cheap alternative to Z87. Whether or not the boards ought to be by design aside, it looks like Intel noticed, and acted fairly quickly to fix it (or deny capability, rather).
I feel bad for anyone who bought a H87/B75 + 4670K and really didn't expect this to happen.
So you can either not update your BIOS, which doesn't seem TOO bad (unless they add some crippling aspect forcing you to) or turn off windows updates, if they 'disguise' it. I wasn't aware BIOS updates could be done via windows update.With regards to actually deploying the update, Intel can be expected to either push the “fix” to relevant motherboard vendors with instructions to release it as a BIOS update, or release it through a Windows Update under the tried and tested guise of a “stability update.”