|Further to the above comments by Othehill. |
My advice is, copy pictures documents to the external hard drive, & regularly update. I use back4sure, I don't think it compresses the files.
I would also copy them to a cloud service, like Gdrive or Skydrive
But, for an easy way to completely restore a broken windows installation, I recommend you create an image of your hard drive, Easus todo can do this, I use Paragon free.
With this, if your pc fails to start due to a windows problem, by restoring the image, will be a lot quicker than than installing windows by dvd then installing program & updates.
It might be an idea to partition your external hard drive, one for the image, the other for pictures & documents.
A thank you would be nice, if I have helped.