True OS and Open BSD

I am currently installing True OS on a 32 GiB  using ZFS  file system.
It cannot be booted on a 16 GiB USB.
Free BSD can be booted with only I GiB.
For full BSD live session one need the 4.5 GiB image on. DVD and a 4 GiB stick.
Do not use USB of less than 4 GiB for a Linux or BSD image.

It is not only Microsoft but there are other alternative operating systems in the computer world.

It all started with BSD and Unix.

Microsoft came in long after Apple which is basically Unix derivative.