There are many ways to copy files over from one location to another on Windows, but one nice free one is provided by Microsoft: SyncToy.
You can use it to keep two directories synchronized, or in the video below, you can see how you can use it to back up your documents.
View the video below, or click here to watch it on YouTube. If you are able to, I recommend that you watch it with HD turned on.
This video on Microsoft SyncToy is part of a series of quick videos on paperless tips and topics. View more in the series here.