Buy a 2TB external drive
Create a couple of top level folders on it. 1 called BasicImage, the other called MyDocs.
Using DriveimageXML, create an image of the current system in the 'BasicImage' folder. That saves it in its current state.
Now, using something like Syncback Free, aim it at your source folders holding music, images, etc. Target folders wiould be subfolders that you create in MyDocs.
Now give it a schedule...maybe every night at 2AM (or whenever). Everything new or changed gets copied to that external, in whatever folder you have selected.
So you have an Image of the system as it exists today, and updating copies of your 'data'.