You can trigger backup and restore operations in the Storage Manager. The Storage Manager is available from the app bar of the timeline.
Independently of any manual backup efforts, we are highly recommending the use of tools that automate backups. For example, if your are storing your memories somewhere in the “Documents” folder, we recommend to use Microsoft’s tool “File History” (http://windows.microsoft.com/en-us/windows-8/how-use-file-history). It’s free and easy to use.