i will answer my own question seeing no one else will....
Hi Minerx117
The 7th gen kaby lake processors only support win10 (and linux). The 6th gen skylake processors support previous versions of windows such as 7 and 8/8.1. Both Skylake and Kabylake can be used with this TB250 board (250 or 270 chipsets). What i have in the package is the skylake celeron, which supports all versions of windows, and it is for that reason why I used it (and its slightly cheaper than the kaby lake version).
You can run linux on either kabylake or skylake processors, but the processor in my package will support win8.1. Where if i had used a kabylake, it would not have supported win8.1. I like the freedom of being able to switch OS's in the future, even to an older OS such as 7 or 8.1 and again, is the main reason why that processor was put into my build. I mention this in my build video also
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
so no worries, you will be good to go with win8.1
Thanks for asking, its a good question. Many people may not realize kabylake does not support older versions of windows. Very mean for microsoft to force win10 on people due to low usage of win10... they should have a better means of getting people to upgrade and not force them.
Best Regards
#Nemo