Okay, I updated the OP and will remove the OS if I sell here.
But an FYI – Windows 10 does not work on the same licensing model as previous versions. The OS fully works if its not activated, the only limitations are purely cosmetic and a watermark.
This is my opinion, but I think some one receiving a laptop which is working and ready for them to test/use (and activate later with their own license key) is a better experience than receiving one with no OS. As long as the seller marks it as not being activated so the buyer is aware.