Whether you love or hate Windows 8's Metro interface, its syncing feature makes it immensely valuable to both people with more than one device, and those who know how frustrating it can be to lose personal data and settings from a crash.
Windows 8 can run a local account, but if you use a Microsoft account -- formerly known as a Windows Live account -- you'll be able to sync some app settings and passwords; Internet Explorer 10 history, preferences, and bookmarks; desktop options such as log-in, lock screen, and colors; search preferences; language preferences; and keyboard and mouse settings.
To set it up, go to the Charms bar, then Settings, and More PC Settings at the bottom of the sidebar. That will open the Windows 8 settings screen. On the left nav, go to Users, then Switch to Microsoft account.
From here, you can enter in your account details, or follow the instructions for creating a new one.
Once you've logged in with your Microsoft account, a new option will be added to PC Settings called Sync your settings. From there, you can toggle not just the data you want to sync, but also prevent syncing from happening when you're on a metered Internet connection.
Even if you have only one Windows 8 device, it's worth using a Microsoft account because you'll be able to resurrect your preferences and data in case of a catastrophic computer failure.