The barebones version of this mini PC does not come with Windows 11 pre-installed. Only the non-barebones versions include Windows 11 out of the box. Since the barebones version lacks RAM and SSD, it also does not have Windows 11 installed. You will need to install Windows 11 yourself by downloading the system image from the manufacturer's support page. Note that the manufacturer does not provide Windows license keys, so you will need to have your own valid key for activation.