The HDD is partitioned and contains two partitions. The C partition is the system partition which contains the Windows OS. The second partition D contains the HDD recover data.
The HDD recovery allows you to set the notebook back to factory settings without the usage of Recover disk.
But it’s strongly recommended to create the recover disk!!! The user manual provides the info about that… in case something would go wrong with the HDD, the recover disk allows you to recover the notebook.
Of course you can delete the D partition if you want but before doing this, you should create the recovery disk.
However, my HDD contains 3 partitions. I created additional one. In my case the C partition contains only the system and single software. My private files like Mp3, movies, etc… are placed on D (second partition).
The third partition (E) contains a folder with games.