This HP Z240 Workstation was sold as "refurbished," and came in a box with "Microsoft Authorized Refurbisher" stickers. The computer did not work correctly at first. After trying many different things to make it work, I discovered that one of the RAM sticks was defective. I removed the RAM and that solved the problem; the computer works flawlessly now. I installed Ubuntu 21.10 on the machine without any problems. Then I discovered the motherboard actually has an nVME M.2 slot! It is located in a very awkward place, but it does work, and I was able to install my operating system on it.The box also contained dongles for wifi and bluetooth, but the wifi dongle was only good for 2.4Ghz, so I replaced it with a PCI-E Wifi adapter, which works much better. I don't need the Bluetooth, so I won't bother with it. Definitely. Possibly. Probably-maybe.