No disk and no delays. With Windows Anytime Upgrade, you can upgrade to a more advanced edition of Windows 7—say from Home Premium to Ultimate—in as little as 10 minutes. That way, you get to take advantage of extra features while keeping your current programs, files, and settings intact.
In the past, upgrading Windows could be a bit of a hassle. In Windows 7, the software you need comes preinstalled. You can buy an upgrade key from an authorized retail store.
Find out about upgrading to Windows 7 from Windows Vista or Windows XP