A copy Microsoft Windows XP Pro.
Unopened.
I found this in a box of old IT stuff in a garage. It is still sealed and has a number of stickers on it which may or may not be the required key. I have no idea. I have covered them for obvious reasons.
I presume whoever buys this will have a better idea than I, but either way, be aware that I can make no promises in that regard.
Sold as is.