• Make sure you’re on the PC you want to upgrade. This must be a PC that is currently running Windows 7, Windows Vista, Windows XP with Service Pack 3 (SP3), Windows 8 Release Preview, Windows 8 Consumer Preview, or Windows Developer Preview. (Windows 8 Setup checks that your PC meets all system requirements before it installs Windows 8.)
• Have your product key handy. You can find it in your online order information, in the confirmation email for your purchase, or on the packaging. The product key will look something like this:
XXXXX- XXXXX- XXXXX- XXXXX- XXXXX
• Make a backup of everything you want to keep. Save it somewhere you can get to it later, like an external drive or a DVD.