= Windows 10 =
There is utility to back up Windows 8/10 systems called "File History". Here is a brief tutorial on how to [http://www.howtogeek.com/74623/how-to-use-the-new-file-history-feature-in-windows-8/ use file history to backup]. The key is to use your HDA for backup, for example a backups share called \\hda\backups share.
We recommend to lower the "keep my backups" option from Forever to less than that, like 6 months or a year. Otherwise, your storage may get full quickly.
= Vista, Windows 7 or 8 =
If you use Windows Vista, Windows 7 or Windows 8, there is a built-in, straightforward way to backup your files (not the OS) regularly to the HDA.