Worth noting that if you are intending passing your PC on to your mate, then the install of Windows you have on it should be uninstalled to remain completely legal. You are licensed to use that copy of Windows, but your mate isn't and the license is not officially transferrable. Have you both read the Microsoft 'End User License Agreement' ? If this then becomes your mate's PC he will need an operating system, and he might choose to buy a Microsoft license or use one of the may alternatives. The copy of Windows will remain licensed to you, and so you will be able to install on it any other PC you have (one other, not many).