Whether you install now or wait until later, Windows Setup will get your PC ready and check for any final things you need to do before actually installing. Take care of each of the items on the list, in order. As you complete each item, the list will automatically refresh.
Once you’re done, you’ll be ready to install the upgrade. You’ll see a recap of what you’ve decided to do. If you need to change anything, click Back, but if you’re ready, click Install.
Your PC will restart several times while Windows 8 is installing. If your PC is currently running Windows 7, your files, apps, and settings will easily transfer to Windows 8. If your PC is running Windows XP or Windows Vista, you'll need to reinstall your apps after you upgrade.