Hi:
I am not sure that will be big enough unless you know right now that you have less than 32 GB of space used.
In any event, type File History using the search tool.
Then on the file history window, click on the Create System Image link and you can make an image of your current installation.
You can keep that updated anytime you want, but you may need a larger storage drive such as a portable HDD.
Also you will need your W8 or W8.1 installation media to access the image you created.
If you do not have a plain W8 or W8.1 installation media, please see the link below for how to create a recovery drive.
You will need a separate USB 256 MB or larger flash drive for this purpose.