The buyer purchased a computer on eBay and a few days later reported that the Windows OS on the computer doesn't seem 'authentic'. This was a certified refurbished Lenovo computer with warranty. Lenovo doesn't sell computers without an OS. When I received the computer back I also verified that the windows was activated. I also offered to speak to the buyer over the phone thinking there was some confusion. Now I realize that this buyer probably just changed his mind and didn't want to pay the return shipping costs. So he came up with a false claim. Of course, he is an 'experienced' ebay user and knows that I can't dispute his claim with eBay.