These have NO operating system BUT have dual Xeons, 16 to 32 Gig DDR4. nVidia Ai graphics with4 Gig video, are RAM expandable to 512 RAM. BUT you MUST to really have knowledge real knowledge. IF you buy one you should change the ownership from USA to yourself so you can get all upgrades to run Windows 11. I gave one to my son in Tacoma, Wa and he switched him Major to forestry instead of computer science like me and he had the top gamer machine in his sphere,which is the reason that I am selling in this fashion