My machine came with US keyboard, mouse, 256GB SATA SSD, and Windows 10 Professional preinstalled. Unfortunately, the processor, even though rather recent, is not officially supported by Windows 11, so you cannot simply upgrade. Another thing to realise, this PC has no HDMI, but two Displayport sockets for your monitor.Nevertheless, you can do a complete fresh install of Windows 11, so far the machine behalves nicely.The machine can be opened with one screw only, inside things are tight but you can easily upgrade RAM (2 banks there) and add a PCIe SSD if you like.All in all, if you are happy with a simple machine and are not into heavy gaming, this PC is worth its money.