I am sorry, but what you seem to say happened does not seem to make sense.
If all you were doing was moving files from the hard drive to the DVD, the Windows 7 boot should not have been effected.
If you restored because, all of a sudden, you could not access the external drive, a restore seems a little bit of overkill. There must be something going on you have not yet explained.
Are there any Digital Rights Management issues involved?
If the external drive has been disconnected, reconnect it. I have seen situations where the Win 7 system depended on drives, like the DVD drive, that would not be expected.