Hi
What you are doing looks like it's creating a recovery partition similar to what a factory created partition would look like.
So essentially the whole partition is what you need to remove.
You might want to make the partition larger then that before you create a new backup on it, my recovery partition is 200 Gb and allows me to have up to 3 backups of my C:\ drive on it.
What you are creating if I understand it correctly would replace you Windows install but nothing else on your C:\ drive and since it could possibly overwrite the whole drive may cause you to lose all of the other data on the drive.
You might want to consider creating a system image using software like EaseUS Todo backup and recovery free version.
It will backup...