I received a warning message "Reconnect your drive. Your files will be temporarily copied to your hard drive until you reconnect you File History drive and run a backup."

How do I do this?

To set up a drive

1. Connect an external drive.

2. Open File History by swiping in from the right edge of the screen, tapping Search (or if you're using a mouse, pointing to the upper-right corner of the screen, moving the mouse pointer down, and then clicking Search), entering File History in the search box, tapping or clicking Settings, and then tapping or clicking File History.

3. Tap or click Turn on.

Refer to this article.

Set up a drive for File History: http://windows.microsoft.com/en-US/windows-8/set-drive-file-history

I had the same message. I had previously done my backup up to an external drive. I had accidently deleted some of the files in the file history. After that, File histpory did not recognize the file location (i.e. did not recognise the external drive).

It asks if you want to connect to a drive. When I said yes, It asked if i wanted to copy the remaining files to the saved location. When I said yes again, it would not connect to the expternal drive. It came up with the warning.

I overcame this by NOT copying the remaining files across to the external drive. It then ran the whole back up as if it was the first time to the external drive.

I am guessing that it required some of the files that had previously been delted and that is why it would not recognise the file location.