Ok, I have windows 7.  I Installed an SSD to run windows and chrome.  I'm using my old Hard drive as mass storage for all my files, pictures, music, etc.  I put all my stuff on an external drive, went through it, cleaned it up, and then reinstalled on my old Hard drive which is now drive E:  How do I set the external hard drive up to keep a backup only drive E:?  I'm not so worried about C: the SSD as I can just reinstall Windows and Chrome and go from there.